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Tamilnadu State Board New Syllabus Samacheer Kalvi 12th Bio Zoology Guide Pdf Chapter 1 Reproduction in Organisms Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 12th Bio Zoology Solutions Chapter 1 Reproduction in Organisms

12th Bio Zoology Guide Reproduction in Organisms Text Book Back Questions and Answers

Question 1.
In which type of parthenogenesis are only males produced?
(a) Arrhenotoky
(b) Thelytoky
(c) Amphitoky
(d) Both a and b
Answer:
(a) Arrhenotoky

Question 2.
Animals giving birth to young ones:
(a) Oviparous
(b) Ovoviviparous
(c) Viviparous
(d) Both a and b
Answer:
(c) Viviparous

Question 3.
The mode of reproduction in bacteria is by ……………..
(a) Formation of gametes
(b) Endospore formation
(c) Conjugation
(d) Zoospore formation
Answer:
(c) Viviparous

Question 4.
In which mode of reproduction variations are seen?
(a) Asexual
(b) Parthenogenesis
(c) Sexual
(d) Both a and b
Answer:
(c) Sexual

Question 5.
Assertion and reasoning questions:
In each of the following questions there are two statements. One is assertion (A) and other is reasoning (R). Mark the correct answer as
A. If both A and R are true and R is correct explanation for A
B. If both A and R are true but R is not the correct explanation for A
C. If A is true but R is false
D. If both A and R are false

I. Assertion: In bee society, all the members are diploid except drones.
Reason: Drones are produced by parthenogenesis.
A B C D
Answer:
(I) A

II. Assertion: Offsprings produced by asexual reproduction are genetically identical to the parent.
Reason: Asexual reproduction involves only mitosis and no meiosis.
A B C D
Answer:
(II) A

III. Assertion: Viviparous animals give better protection to their offsprings.
Reason: They lay their eggs in the safe places of the environment.
A B C D
Answer:
(III) C

Question 6.
Name an organism where cell division is itself a mode of reproduction.
Answer:
Amoeba

Question 7.
Name the phenomenon where the female gamete directly develops into a new organism with an avian example.
Answer:
Parthenogenesis is the phenomenon where the unfertilized female gamete (egg) develops into a new individual.
e.g. Turkey

Question 8.
What is parthenogenesis? Give two examples from animals.
Answer:
Development of an egg into a complete individual without fertilization is known as parthenogenesis. It was first discovered by Charles Bonnet in 1745.
E. g. Honey bees, Aphis.

Question 9.
Which type of reproduction is effective – Asexual or sexual and why?
Answer:
Sexual reproduction is highly effective than asexual reproduction since the offsprings produced are genetically different from parents causing variations. Variation leads to evolution.

Question 10.
The unicellular organisms which reproduce by binary fission are considered immortal. Justify.
Answer:
In unicellular organisms during binary fission, the entire cell (organism) divides completely to form two daughter cells which later on develop into adult and the process goes on repeatedly during each division leading to immortality of cell (organism). Hence unicellular organisms like amoeba are ‘biologically immortal’.

Question 11.
Why is the offspring formed by asexual reproduction referred as a clone?
Answer:
Offsprings developed by asexual reproduction are referred to as clones since they are genetically & morphologically similar to this parent.

Question 12.
Why are the offsprings of oviparous animal at a greater risk as compared to offsprings of viviparous organisms?
Answer:
Oviparous animals are egg-layers. The eggs containing embryo are laid out of their body and are highly susceptible to environmental factors (temperature, moisture etc.) and predators. Whereas, in viviparous animals, the embryo develops inside the body of female and comes out as young ones. Hence offsprings of oviparous animals are at risk compared to viviparous animal.

Question 13.
Give reasons for the following:

1. Some organisms like honey bees are called parthenogenetic animals
2. A male honey bee has 16 chromosomes whereas its female has 32 chromosomes

Answer:

1. Among honey bees, the queen bee and worker bees develop from fertilized eggs whereas the drones develop from unfertilized eggs. Hence the honey bees are parthenogenetic animals showing incomplete parthenogenesis.
2. Female honey bees (Queen or worker bees) are diploid having 32 chromosomes since they develop from the fertilized egg. On the other hand, the male honey bees (drones) develop from unfertilized egg possessing only 16 chromosomes (i.e., Haploid)

Question 14.
Differentiate between the following:
(a) Binary fission in amoeba and multiple fission in Plasmodium
(b) Budding in yeast and budding in Hydra
(c) Regeneration in lizard and Planaria
Answer:
(a) Binary fission in amoeba and multiple fission in Plasmodium

(b) Budding in yeast and budding in Hydra

(c) Regeneration in lizard and Planaria

Question 15.
How is juvenile phase different from reproductive phase?
Answer:

Question 16.
What is the difference between syngamy and fertilization?
Answer:
Syngamy & fertilization both are more similar terms with a difference that syngamy refers to the process of fusion of two gametes forming zygote while fertilization refers to the process of being fertile.

12th Bio Zoology Guide Reproduction in Organisms Additional Important Questions and Answers

12th Bio Zoology Guide Reproduction in Organisms One Mark Questions and Answers

I. Choose the Correct Answer:

Question 1.
Transverse binary fission is noticed in…………………………
(a) Amoeba
(b) Planaria
(c) Ceratium
(d) Vorticella
Answer:
(b) Planaria

Question 2.
Multiple fission occurring in the oocyte of plasmodium is called……………………….
(a) Schizogony
(b) Merogamy
(c) Syngamy
(d) Sporogony
Answer:
(d) Sporogony

Question 3.
Taenia solium requires ……………………….as a secondary host to complete its life cycle.
(a) Mosquito
(b) pig
(c) dog
(d) human
Answer:
(b) pig

Question 4.
Which type of parthenogenesis only females are produced?
(a) Arrhenotoky
(b) Amphitoky
(c) Thelytoky
(d) Both (a) and (b)
Answer:
(c) Thelytoky

Question 5.
Which among the following animal is not a continuous breeder?
(a) Hen
(b) Rabbit
(c) Honey bees
(d) Frogs
Answer:
(d) Frogs

Question 6.
Match the following.

Answer:
a – in, b -iv, c-ii, d-i

Question 7.
Identify the incorrect statement regarding parthenogenesis.
(a) Development of sperm without fertilization.
(b) It was first discovered by Charles Bonnet.
(c) Honey bees exhibit incomplete parthenogenesis.
(d) Amphitoky is a type of natural parthenogenesis.
Answer:
(a) Development of sperm without fertilization.

Question 8.
Oblique binary fission is seen in……………………….
Answer:
Dinoflagellates

Question 9.
The process by which gravid proglottids of tapeworm gets cut off is called…………………………..
Answer:
apolysis

Question 10.
The concept of regeneration was first noticed in……………………….
Answer:
Hydra

Question 11.
Fusion of small sized, morphologically different gametes is called……………………….
Answer:
merogamy

Question 12.
Identify the wrong statement.
(a) Oviparous animals lays eggs.
(b) Viviparous animals give rise to young ones.
(c) Ovoviviparous animals lays eggs and then hatch it to young ones.
(d) Amphibians are oviparous animals.
Answer:
(c) Ovoviviparous animals lays eggs and then hatch it to young ones.

Question 13.
Assertion (A): Organisms show three phases in their life cycle.
Reason (R): Juvenile phase is a degenerative phase.
(a) A is correct R but is incorrect. ‘
(b) Both A and R are correct
(c) R is the correct explanation for A
(d) A is not correct but R is correct
Answer:
(a) A is correct R but is incorrect.

Question 14.
Match the statements.

Answer:
a – iii, b – iv, c-i,d- ii.

Question 15.
The ploidy of males produced by arrhenotoky parthenogenesis is
Answer:
haploid

Question 16.
Identify the mismatched pair.
(a) Paedogenesis- Liver fluke
(b) Strobilation- Aurelia
(c) Amphitoky- Honey bee
(d) Encystment- Amoeba
Answer:
(c) Amphitoky – Honey bee

Question 17.
Identify the proper sequence.
(a) juvenile phase, senescent phase, vegetative phase
(b) juvenile phase, maturity phase, senescent phase
(c) vegetative phase, maturity phase, juvenile phase
(d) senescent phase, juvenile phase, vegetative phase
Answer:
(b) juvenile phase, maturity phase, senescent phase

Question 18.
Match the following:

Answer:
a -iv, b-iii, c- ii, d-i

Question 19.
Which of the following types of asexual reproduction is noticed in Amoeba?
(a) Sporulation
(b) Encystment
(c) Binary fission
(d) All the above
Answer:
(d) All the above

Question 20.
Pick out the organism whose fertilization occurs internally.
(a) reptiles
(b) sponges
(c) pisces
(d) amphibians
Answer:
(a) reptiles

Question 21.
Assertion (A): Asexual reproduction is called blastogenic reproduction.
Reason (R): It is accomplished by mitotic and meiotic divisions.
(a) A and R are correct
(b) A is correct but R is incorrect
(c) Both A and R are incorrect
(d) R is the correct explanation for A
Answer:
(b) A is correct but R is incorrect

Question 22.
Egg laying hen is an example for
(a) Thelytoky
(b) Ovovivipary
(c) Vivipary
(d) Ovipary
Answer:
(d) Ovipary

Question 23.
Assertion (A): Syngamy refers to the fusion of two haploid gametes.
Reason (R): Syngamy leads to zygote formation.
(a) A and R are correct.
(b) A and R are incorrect.
(c) R is not the right explanation for A
(d) A is correct but R is incorrect.
Answer:
(a) A and R are correct.

Question 24.
Human beings are an example for ………………..breeders.
Answer:
continuous

12th Bio Zoology Guide Reproduction in Organisms Two Marks Questions and Answers

Question 1.
Why asexual reproduction is called somatogenic reproduction?
Answer:
Asexual reproduction is usually by amitotic or mitotic division of the somatic (body) cells, – hence is also known as somatogenic or blastogenic reproduction.

Question 2.
Name the four types of fission seen in animals.
Answer:
Binary fission, Multiple fission, Sporulation and Strobilation.

Question 3.
Define fission.
Answer:
Fission is the division of the parent body into two or more identical daughter individuals.

Question 4.
Differentiate between transverse binary fission and longitudinal binary fission.
Answer:
Transverse binary fission

1. Plane of division runs along the transverse axis of the organism
2. Example: Paramecium

Longitudinal binary fission :

1. Plane of division runs along the longitudinal axis of the organism.
2. Example: Euglena

Question 5.
Define Plasmotomy with example.
Answer:
Plasmotomy is the division of multinucleated parent into many multinucleate daughter individuals with the division of nuclei. Nuclear division occurs later to maintain normal number of nuclei. Plasmotomy occurs in Opalina and Pelomyxa (Giant Amoeba).

Question 6.
What do you mean by regeneration in living organisms? Mention its types.
Answer:
Regeneration is the regrowth of injured region.
It is of two types

1. Morphallaxis
2. Epimorphosis.

Question 7.
How is the fertilization of amphibians differs from aves based on site?
Answer:
In amphibians the fertilization is external (taking place outside the body of female organism) whereas internal fertilization takes place in aves.

Question 8.
What is Paedogamy?
Answer:
Paedogamy is the sexual union of young individuals produced immediately after the division of the adult parent cell by mitosis.

Question 9.
Write a brief note on conjugation.
Answer:
Conjugation is the temporary union of the two individuals of the same species. During their union both individuals, called the conjugants exchange certain amount of nuclear material (DNA) and then get separated. Conjugation is common among ciliates, e.g. Paramecium, Vorticella and bacteria (Prokaryotes).

Question 10.
Classify animal breeding based on time.
Answer:
On the basis of time, breeding animals are of two types: seasonal breeders and continuous bud enlarges, develops a mouth and a circle of tentacles at its free end. When fully grown, the breeders. Seasonal breeders reproduce at particular period of the year such as frogs, lizards, most birds, deers etc., Continuous breeders continue to breed throughout their sexual maturity e.g. honey bees, poultry, rabbit etc.

Question 11.
Define Vivipary.
Answer:
Vivipary is a condition in which animals give rise to live young ones after being nourished in the uterus though the placenta. E.g. human.

Question 12.
List out the four types of binary fission.
Answer:

1. Simple irregular binary fission
2. Transverse binary fission
3. Longitudinal binary fission
4. Oblique binary fission

Question 13.
Repeated fission is a type of multiple fission. Yes or No? Why?
Answer:
Yes. If multiple fission produces four or many daughter individuals by equal cell division and the young ones do not separate until the process is complete, then this division is called repeated fission e.g. Vorticella.

Question 14.
Define apolysis.
Answer:
The detachment of gravid proglottids either singly or in groups from the body of tapeworm is called apolysis.

12th Bio Zoology Guide Reproduction in Organisms Three Marks Questions and Answers

Question 15.
Compare schizogony with sporogony of plasmodium.
Answer:
Schizogony

1. In schizogony, the multiple fission occurs in the schizont.
2. It results in the formation of merozoites.

Sporogony :

1. In sporogony, the multiple fission occurs in the oocyte.
2. It results in the formation of sporozoites.

Question 16.
Write a short note on encystment in amoeba.
Answer:
During unfavorable conditions (increase or decrease in temperature, scarcity of food) Amoeba withdraws its pseudopodia and secretes a three-layered, protective, chitinous cyst wall around it and becomes inactive. This phenomenon is called encystment. When conditions become favourable, the encysted Amoeba divides by multiple fission and produces many minute amoebae called pseudopodiospore or amoebulae. The cyst wall absorbs water and breaks off liberating the young pseudopodiospores, each with a fine pseudopodia. They feed and grow rapidly to lead an independent life.

Question 17.
How exogenous buds are developed by Hydra?
Answer:
When buds are formed on the outer surface of the parent body, it is known as exogenous budding e.g. Hydra. In Hydra when food is plenty, the ectoderm cells increase and form a small elevation on the body surface. Ectoderm and endoderm are pushed out to form the bud. The bud contains an interior lumen in continuation with the parent’s gastrovascular cavity. The bud enlarges, develops a mouth and a circle of tentacles at its free end. When fully grown, the bud constricts at the base and finally separates from the parent body and leads an independent life.

Question 18.
Apolysis favours Taenia solium. How?
Answer:
In the tapeworm, Taenia solium the gravid (ripe) proglottids are the oldest at the posterior end of the strobila. The gravid proglottids are regularly cut off either singly or in groups from the posterior end by a process called apolysis. This is very significant since it helps in transferring the developed embryos from the primary host (man) to find a secondary host (pig).

Question 19.
What is autogamy?
Answer:
– In autogamy, the male and female gametes are produced by the same cell or same organism and both the gametes fuse together to form a zygote e.g. Actinosphaerium and Paramecium.

Question 20.
What is exogamy?
Answer:
In exogamy, the male and female gametes are produced by different parents and they fuse to form a zygote. So it is biparental. e.g. Human – dioecious or unisexual animal.

Question 21.
Give the definition for

1. Arrhenotoky
2. Thelytoky
3. Amphitoky

Answer:

1. Arrhenotoky: In this type only males are produced by parthenogenesis, eg: honey bees
2. Thelytoky: In this type of parthenogenesis only females are produced by parthenogenesis. e.g.: Solenobia
3. Amphitoky: In this type parthenogenetic egg may develop into individuals of any sex. e.g.: Aphis.

Question 22.
What is Incomplete parthenogenesis? Explain with example.
Answer:
Incomplete parthenogenesis is a type of reproduction in which both sexual reproduction and parthenogenesis occurs. Example: In honey bees, the fertilized eggs develop into queen bee and worker bees, whereas the unfertilized eggs develop into drones (male).

Question 23.
Explain briefly the nature of Ovovivipary.
Answer:
In Ovoviviparous animals, the embryo develops inside the egg and remains in the mother’s body until they are ready to hatch. This method of reproduction is similar to viviparity but the embryos have no placental connection with the mother and receive their nourishment from the egg yolk. Ovoviviparity is seen in fishes like sharks.

Question 24.
Point out any six modes of asexual reproduction seen in animals.
Answer:

1. fission
2. budding
3. fragmentation
4. sporulation
5. regeneration
6. gemmule formation.

Question 25.
Enumerate the types of syngamy.
Answer:

1. Autogamy
2. Exogamy
3. Hologamy
4. Paedogamy
5. Merogamy
6. Isogamy
7. Anisogamy
8. Conjugation

Question 26.
Name the types of animals based on embryonic development with an example for each.
Answer:

1. Oviparous animals e.g., Birds
2. Viviparous animals e.g., Human beings
3. Ovoviviparous animals e.g., Shark

Question 27.
Write a short note on the phases of the life cycle.
Answer:

1. Juvenile phase – Period of growth between birth of an individual and reproductive maturity.
2. Reproductive phase – Period of growth when an organism attain reproductive maturity and produces new offsprings.
3. Senescent plane – Period of growth when the structure and functioning of body starts degenerating.

Question 28.
What is Paedogenesis?
Answer:
In paedogenetic parthenogenesis (paedogenesis) the larvae produce a new generation of larvae ” by parthenogenesis. It occurs in the sporocysts and Redia larvae of liver fluke. It is also seen in the larvae of some insects, e.g. Gall fly.

Question 29.
Draw and label a gemmule of sponge.
Answer:

Question 30.
Differentiate between asexual and
Answer:
Asexual Reproduction

1. Involves only one parent
2. Only the mitotic cell division takes place.
3. Offsprings are genetically identical to parent.
4. Gametes are not produced

Sexual reproduction.

1.  Involves two parents (male & female)
2. Both mitosis & meiosis takes place.
3. Offsprings genetically differ from the parents.
4. Gametes are produced.

12th Bio Zoology Guide Reproduction in Organisms Five Marks Questions and Answers

Question 31.
Describe the regeneration process noticed in living organism.
Answer:
Regeneration is regrowth in the injured region. Regeneration was first studied in Hydra by Abraham Trembley in 1740. Regeneration is of two types, morphallaxis and epimorphosis. In morphallaxis the whole body grows from a small fragment e.g. Hydra and Planaria. When Hydra is accidentally cut into several pieces, each piece can regenerate the lost parts and develop into a whole new individual.

The parts usually retain their original polarity, with oral ends, by developing tentacles and aboral ends, by producing basal discs. Epimorphosis is the replacement of lost body parts. It is of two types, namely reparative and restorative regeneration. In reparative regeneration, only certain damaged tissue can be regenerated, whereas in restorative regeneration severed body parts can develop, e.g. star fish, tail of wall lizard.

Question 32.
Given an account on following terms, (a) Hologamy (A) Isogamy (c) Anisogamy . (d) Merogamy (e) Paedogamy
Answer:

1. Hologamy: In Hologamy, the adult individuals do not produce gametes, but they themselves act as gametes and fuse to form new individuals. E.g.: Trichonympha
2. Isogamy: Fusion of morphologically & physiologically similar gametes. E.g.: Monocystis .
3. Anisogamy: Fusion of morphologically & physiologically dissimilar gametes. Eg: Vertebrates.
4. Merogamy: Fusion of small sized morphologically different gametes (merogametes)
5. Paedogamy: Fusion of young individuals produced immediately after the mitotic division of adult parent cell.

Higher Order Thinking Skills (HOTs) Questions

Question 1.
Under threat or attack, the garden lizard loses a part of its tail which trembles and avert the attention of predators, so that the lizard escapes later the tail regrown for the lizard. The same phenomenon can also be noticed in organisms like starfish etc. What do you call this phenomenon? Define it.
Answer:
Regeneration is the regrowth in the injured region.

Question 2.
Complete the table.

Answer:
A – Only males ; B – Only Females ; C – Both Males & Females

Question 3.
In Vivipary, how the developing embryoes are nourished?
Answer:
In Vivipary, the embryo develops inside the womb of females body, hence they are nourished by the mother through placenta.

Question 4.
How Charles Bonnet and Abraham Trembley contributed to the Biological field?
Answer:
Charles Bonnet discovered the process of parthenogenesis. .
Abraham Trembley was the first to study the concept of Regeneration in the Hydra.

Question 5.
‘A’ and ‘B’ are the male & female sex cells respectively which look alike and performs similar functions. ‘A’ and ‘B’ fuse to form a new individual ‘D\ Which type of gametic fusion does this represent? Give an example.
Answer:
Isogamy. Eg: Monocystis

Question 6.
Complete the flow chart by mentioning the ploidy of cells in boxes.

Answer:
Queen Bee, Worker Bee – Diploid (2n)
Drones (Male Bee), Egg, sperm – Haploid (n)

Question 7.
Meiosis is a type of cell division where the chromosomal number is reduced to half the number daughter cells. Which type of cellular division occurs in the drones to produces spermatozoa? Why?
Answer:
The gonadal cells of drones undergo mitosis to form sperms. Because the drones are haploid in nature since they develop from unfertilized eggs. To avoid further reduction in chromosome no. and maintain the chromosomal constancy, (instead of undergoing meiosis), mitosis will take place leading to formation of haploid gametes.

Tamilnadu State Board New Syllabus Samacheer Kalvi 12th Bio Botany Guide Pdf Chapter 7 Ecosystem Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 12th Bio Botany Solutions Chapter 7 Ecosystem

12th Bio Botany Guide Ecosystem Text Book Back Questions and Answers

I. Choose the most suitable answer from the given four alternatives and write the option code and the corresponding answer.

Question 1.
Which of the following is not a abiotic component of the ecosystem?
a. Bacteria
b. Humus
c. Organic compounds
d. Inorganic compounds
Answer:
d. Inorganic compounds

Question 2.
Which of the following is / are not a natural ecosystem?
a. Forest ecosystem
b. Rice field
c. Grassland ecosystem
d. Desert ecosystem
Answer:
b. Rice field

Question 3.
Pond is a type of
a. forest ecosystem
b. grassland ecosystem
c. marine ecosystem
d. fresh water ecosystem
Answer:
d. fresh water ecosystem

Question 4.
Pond ecosystem is
a. not self sufficient and self regulating
b. partially self sufficient and self regulating
c. self sufficient and not self regulating
d. self sufficient and self regulating
Answer:
d. self sufficient and self regulating

Question 5.
Profundal zone is predominated by heterotrophs in a pond ecosystem, because of
a. with effective light penetration
b. no effective light penetration
c. complete absence of light
d. a and b
Answer:
b. no effective light penetration

Question 6.
Solar energy used by green plants for photosynthesis is only
a. 2-8%
b.2-10%
c.3-10%
d.2-9%
Ans :
b. 2 – 10%

Question 7.
Which of the following ecosystem has the highest primary productivity?
a. Pond ecosystem
b. Lake ecosystem
c. Grassland ecosystem
d. Forest ecosystem
Answer:
d. Forest ecosystem

Question 8.
Ecosystem consists of
a. decomposers
b. producers
c. consumers
d. all of the above
Answer:
d. all of the above

Question 9.
Which one is in descending order of a food chain
a. Producers →  Secondary consumers → Primary consumers→  Tertiary consumers
b. Tertiary consumers →  Primary consumers →  Secondary consumers →  Producers
c. Tertiary consumers →  Secondary consumers →  Primary consumers→  Producers
d. Tertiary consumers → Producers →  Primary consumers →  Secondary consumers
Answer:
c. Tertiary consumers →  Secondary consumers →  Primary consumers→  Producers

Question 10.
Significance of food web is/are
a. it does not maintain stability in nature
b. it shows patterns of energy transfer
c. it explains species interaction
d. b and c
Answer:
d. b and c

Question 11.
The following diagram represents

a. pyramid of number in a grassland ecosystem
b. pyramid of number in a pond ecosystem
c. pyramid of number in a forest ecosystem
d. pyramid of biomass in a pond ecosystem
Answer:
c. pyramid of number in a forest ecosystem

Question 12.
Which of the following is / are not the mechanism of decomposition
a. Eluviation
b. Catabolism
c. Anabolism
d. Fragmentation
Answer:
c. Anabolism

Question 13.
Which of the following is not a sedimentary cycle
a. Nitrogen cycle
b. Phosphorous cycle
c. Sulphur cycle
d. Calcium cycle
Answer:
a. Nitrogen cycle

Question 14.
Which of the following are not regulating services of ecosystem services
i) Genetic resources
ii) Recreation and aesthetic values
iii) Invasion resistance
iv) Climatic regulation
a. i and iii
b. ii and iv
c.iandii
d. iandiv
Answer:
c. i and ii

Question 15.
The productivity of the profundal zone will be low. Why?
Answer:
The producers of the pond ecosystem depend on phytoplankton through photosynthesis. The profundal zone lies below the limnetic zone with no effective light penetration, hence the productivity rate is very low.

Question 16.
Discuss the gross primary productivity is more efficient than net primary productivity.
Grass primary productivity (GPP)
Answer:
The grass primary productivity is the total amount of food energy (or) biomass produced by autotrophs through the process of photosynthesis without respiratory loss in the plant.

Net primary productivity (NPP)

• But the net primary productivity is the proportion of energy, which remains after respiration loss from the gross primary productivity in the plant. NPP = GPP – Respiration
• So, gross primary productivity is more efficient than net primary productivity.

Question 17.
Pyramid of energy is always upright. Give reasons
Answer:
The energy pyramid represents a successive energy flow at each trophic level in an ecosystem. There is a gradual decrease in energy transfer at successive tropic levels from producers to higher levels, hence the pyramid of energy is always upright.

Question 18.
What will happen if all producers are removed from ecosystem?
Answer:

• The removal of all the producers would cause the collapse of the entire food web.
• Primary consumers (or) herbivores, which feed on producers directly would die off because they would have nothing to eat.
• All the other animals in the food web would die too, because their food supplies would have gone.
• The population of the consumers would fall as the population of the producer fell.
• Producers are maintaining C02 and oxygen level in the atmosphere.
• If the producers are removed C02 and 02 cycle will be in imbalance in the atmosphere.
• It will leads to the depletion of respiratory gas oxygen as it is a by product of photosynthesis

Question 19.
Construct the food chain with the following data. Hawk, plants, frog, snake, grasshopper.
Answer:

• Food chain with plants → grasshopper → frog → snake → hawk
• The movement of energy from producers upto top carnivores is known as food chain.
• In this food chain energy flows from producers (plants) to primary consumers (grasshopper) to secondary consumer (frog) to tertiary consumer (snake) to predator (hawk)
• It shows linear network link.

Question 20.
Name of the food chain which is generally present in all type of ecosystem. Explain and write their significance.
Answer:
Detritus food chain is generally present in all type of ecosystem.

Detritus food chain:
This type of food chain begins with dead organic matter which is an important source of energy. A large amount of organic matter is derived from dead plants, animals, and their excreta. This type of food chain is present in all ecosystems.

The transfer of energy from the dead organic matter, is transferred through a series of organisms called detritus consumers (detritivores)- small carnivores – large (top) carnivores with repeated eating and being eaten respectively. This is called the detritus food chain.

Significance:

• The detritus (dead plants, animals and their excreta) are breakdown into simple organic matter by the decomposers.
• It is an essential process for recycling and balancing the nutrient pool in an ecosystem.

Question 21.
Shape of pyramid in a particular ecosystem is always different in shape. Explain with example.
Answer:

In a forest ecosystem the pyramid of number is spindle in shape, it is because the base (T₁) of the pyramid occupies large sized trees (Producer) which are lesser in number. Herbivores (T₂) (Fruit-eating birds, elephant and deer) occupying second trophic level, are more in number than the producers. In final trophic level (T₄), .tertiary consumers (lion) are lesser in number than the secondary consumer (T₃) (fox and snake).

Question 22.
Generally human activities are against to the ecosystem, whereas you a student how will you help to protect the ecosystem?
Answer:
To protect the ecosystem, we have to practice the following in our daily life.

• Buy and use only eco-friendly products and recycle them.
• Grow more trees.
• Choose sustained farm products (vegetables, fruits, greens, etc.) > Reduce the use of natural resources.
• Recycle the waste and reduce the amount of waste you produce.
• Reduce consumption of water and electricity.
• Reduce or eliminate the use of household chemicals and pesticides.
• Maintain your cars and vehicles properly. (In order to reduce carbon emission)
• Create awareness and educate about ecosystem protection among your friends and family members and ask them to find out solution to minimize this problem.

Question 23.
Generally in summer the forest are affected by natural fire. Over a period of time it recovers itself by the process of successions. Find out the types of succession and explain.
Answer:

1. Primary succession:
The development of plant community in a barren area where no community existed before is called primary succession. The plants which colonize first in a barren area is called pioneer species or primary community or primary colonies. Generally, Primary succession takes a very long time for the occurrence in any region.
Example: Microbes, Lichen, Mosses.

2. Secondary succession:
The development of a plant community in an area where an already developed community has been destroyed by some natural disturbance (Fire, flood, human activity) is known as secondary succession.

Generally, This succession takes less time than the time taken for primary succession. Example: The forest destroyed by fire may be re-occupied by herbs over period of times.

3. Autogenic succession:
Autogenic succession occurs as a result of biotic factors. The vegetation reacts with its environment and modifies its own environment causing its own replacement by new communities. This is known as autogenic succession.

Example: In forest ecosystem, the larger trees produce broader leaves providing shade to the forest floor area. It affects the shrubs and herbs which require more light (heliophytes) but supports the shade tolerant species (sciophytes) to grow well.

4. Allogenic succession:
Allogeneic succession occurs as a result of abiotic factors. The replacement of existing community is caused by other external factors (soil erosion, leaching, etc.,) and not by existing organisms.

Example : In a forest ecosystem soil erosion and leaching alter the nutrient value of the soil leading to the change of vegetation in that area.

5. Autotrophic succession:
If the autotrophic organisms like green plants are dominant during the early stages of succession it is called autotrophic succession, this occurs in the habitat which is rich in inorganic substances. Since, green plants dominate in the beginning of this succession, there is a gradual increase in organic matter and subsequently the energy flow in the ecosystem.

6. Heterotrophic succession:
If heterotrophic organisms like bacteria, fungi, actinomycetes, and animals are dominant during the early stages of succession it is called heterotrophic succession. Such a succession takes place in organic habitats. Since heterotrophs dominate in the beginning of such succession, there will be a gradual decrease in the energy content.

Question 24.
Draw a pyramid from following details and explain in brief.
Quantities of organisms are given – Hawks – 50, plants – 1000. rabbit and mouse – 250 +250, pythons and lizard- 100 + 50 respectively.
Answer:

• A graphical representation of the amount of organic material (biomass) present at each successive trophic level in an ecosystem is called pyramid of biomass.
• In grassland and forest ecosystems there is a gradual decrease in biomass of organisms at successive trophic levels from producers to top carnivores (tertiary consumer)
• Therefore these two ecosystems show pyramids as upright

1. No.of producers → 1000
2. No.of primary consumers → 500
3. No.of secondary consumer → 150
4. No.of the tertiary consumer is lesser than Secondary consumers (50)

Question 25.
Various stages of succession are given below. From that rearrange them accordingly. Find out the type of succession and explain in detail.
Reed-swamp stage, phytoplankton stage, shrub stage, submerged plant stage, forest stage, submerged free-floating stage, marsh meadow stage.
Answer:
Reed-swamp stage, phytoplankton stage, shrub stage, submerged plant stage, forest stage, submerged free floating stage and marsh medow stage.

(1) Phytoplankton stage – It is the first stage of succession consisting of the pioneer community like blue green algae, green algae, diatoms, bacteria, etc., The colonization of these organisms enrich the amount of organic matter and nutrients of pond due to their life activities and death. This favors the development of the next serai stages.

(2) Submerged plant stage – As the result of death and decomposition of planktons, silt brought from land by rain water, lead to a loose mud formation at the bottom of the pond. Hence, the rooted submerged hydrophytes begin to appear on the new substratum.
Example: Vallisneria and Hydrilla etc. The death and decay of these plants will build up the substratum of pond to become shallow.

(3) Submerged free floating stage – During this stage, the depth of the pond will become almost 2-5 feet Hence, the rooted hydrophytic plants and with floating large leaves start colonising the pond.
Example: Rooted floating plants like Nelumbo, Nymphaea and some free floating species like Azolla, and Pistia are also present in this stage. By death and decomposition of these plants, further the pond becomes more shallow.

(4) Reed-swamp stage – It is also called an amphibious stage. During this stage, rooted floating plants are replaced by plants which can live successfully in aquatic as well as aerial environment.
Example: Typha, Phragmites, Sagittaria and Scirpus etc. At the end of this stage, water level is very much reduced, making it unsuitable for the continuous growth of amphibious plants.

(5) Marsh meadow stage – When the pond becomes swallowed due to decreasing water level, species of Cyperaceae and Poaceae colonise the area. They form a mat-like vegetation with the help of their much branched root system. This leads to an absorption and loss of large quantity of water. At the end of this stage, the soil becomes dry and the marshy vegetation disappears gradually and leads to shurb stage.

(6) Shrub stage – Here areas are invaded by terrestrial plants like shrubs (Salix and Comus) and trees (Populus and Alnus). These plants absorb large quantity of water and make the habitat dry. Further, the accumulation of humus with a rich flora of microorganisms produce minerals in the soil, ultimately favouring the arrival of new tree species in the area.

(7) Forest stage – It is the climax community of hydrosere. A variety of trees invade the area and develop any one of the diverse type of vegetation.
Example.Temperate mixed forest (Ulmus, Acer and Quercus), Tropical rain forest (Artocarpus and Cinnamomum ) and Tropical deciduous forest (Bamboo and Tectona).

12th Bio Botany Guide Ecosystem Additional Important Questions and Answers

I. Choose the correct answer

Question 1.
The most stable and productive ecosystem seen on the earth is _____
a. Mangrove ecosystem
b. Grassland ecosystem
c. Pond ecosystem
d. Forest ecosystem
Answer:
d. Forest ecosystem

Question 2.
In an ecosystem, the energy flow is always
a. Unidirectional
b. Top to bottom
c. Chain form
d. Multi directional
Answer:
a. Unidirectional

Question 3.
Grass 2 Goat 2 Man. This is the grazing food chain choose the correct option.
a. Goat is primary producer, secondary trophic level and herbivore
b. Grass is a primary producer, herbivore, and first trophic level.
c. Goat is a primary consumer, herbivore, second trophic level
d. Goat is a primary consumer, herbivore, first trophil level
Answer:
c. Goat is a primary consumer, herbivore, second trophic level

Question 4.
Choose the incorrect statement from following
a. Pyramid of energy is always upright
b. In grass land and forest ecosystem pyramid of biomass as upright.
c. Pyramid of number shows three different shape of pyramids like upright, spindle and inverted
d. Food web is used for the construction of ecological pyramid.
Answer:
d. Food web is used for the construction of ecological pyramid.

Question 5.
Assertion : If the decomposers were removed completely from the ecosystem the functioning of ecosystem will be adversely affected.
Reason : The cycling of nutrients between abiotic and biotic components will be blocked
a. A and R are correct
b. A and R are not correct
c. A is correct R is wrong
d. R is not a correct explanation for A
Answer:
a. A and R are correct

Question 6.
Assertion : An ecological pyramid is a diagrammatic (or) graphic representation of the trophic structure and function.
Reason : Various trophic levels of a food chain are considered in ecological pyramid.
a. Both are not correct
b. R is not related to A
c. Both A and R are wrong
d. R is the correct explanation of A
Answer:
d. R is the correct explanation of A

Question 7.
Match the following
Read this statement and fill it with correct (A) and (B)

Carbon stored in fossil fuel is ……(A)……….. and carbon stored in the biosphere is …………..(B)……..
The only one correct option for the two blank is

Answer:
b. Grey carbon – Green carbon

Question 8.
Match the following and find the correct answer

a. (i) – B; (ii) – C; (iii) – D; (iv) – A
b. (i) – C; (ii) – D; (iii) – B; (iv) – A
c. (i) – B; (ii) – A; (iii) – D; (iv) – C
d. (i) – D; (ii) – C; (iii) – B; (iv) – A
Answer:
d. (i) – D; (ii) – C; (iii) – B; (iv) – A

Question 9.
Choose the incorrect pair

Answer:
d. Fragmentation – Release of inorganic nutrients from the humus.

Question 10.
Choose the correct pair

a. B and C
b. A and C
c. B, C and D
d. A, B and D
Answer:
d. A, B and D

Question 11.
The plants which colonize first in a barren …………..
area is called
a. Pioneers
b. Serai
c. Autogenic
d. Allogenic
Answer:
a. Pioneers

Question 12.
The term ‘ecosystem’ was proposed by……………..in the year 1935.
a. A.G. Hoxley
b. A.G.Tansley
c. Odum
d. Lindeman
Answer:
b. A.G. Tansley

Question 13.
The position of organisms in food chain is refers to
a. Ecosystem
b. Trophic level
c. Food chain
d. Ten percent law
Answer:
b. Trophic level

Question 14.
Temperate mixed forest, tropical rain forest tropical deciduous forest are
a. Climax communities
b. T ertiary communities
c. Primary communities
d. Secondary communities
Answer:
a. Climax communities

Question 15.
Assertion and Reason
Assertion : Photosynthetically active radiation (PAR) which is between the range of 400 – 700 nm wave length.
Reason : At night PAR is zero and during midday in the summer, PAR often reaches 2000 – 3000 millimoles/square meter/second
a. R does not explains A
b. R explaining A
c. A is correct R is wrong
d. Both A and R are wrong
Answer:
a. R does not explains A

Question 16.
Choose the correct statement:

Question 17.
Choose the correct statement
a. Only 2 – 10% of solar energy is used by green plants for photo synthesis
b. Only 56% of the solar energy is used by green plants for photosynthesis.
c. Productivity can be expressed in terms of kcal / m2 / 10 year
d. Limnology is the study about ocean.
Answer:
a. Only 2 – 10% of solar energy is used by green plants for photo synthesis

Question 18.
Blue carbon ecosystems is related to …………….
a. Carbon sequestration
b. Productivity
c. Visibility
d. Phosphorus cycle
Answer:
a) Carbon sequestration

Question 19.
Choose the correct pair related to this statement
Secondary productivity can be defined as
a. Amount of energy in the tissues of consumer (or) heterotrophs
b. Amount of biomas formation
c. Rate of energy formation
d. Rate of energy utilization
Answer:
a. Amount of energy in the tissues of consumer (or) heterotrophs

Question 20.
Which one of the following will be the shape of the pyramid. If you consider the following statement.
“No. of fruit eating birds, elephant, deer depends on large sized tree (producer) which are lesser in number and lesser number of secondary consumer (fox and snake) and final trophic level tertiary consumer lion.

Answer:
d.

Question 21.
Choose the odd one out
a. Flagship species
b. Rehabilitation
c. Maintaining biodiversity
d. Anthropogenic activities
Answer:
d. Anthropogenic activities

Question 22.
Ecological succession refers to …………………
a. Gradual, fairly changes and pH development of a given area
b. Linking of ecosystem
c. Energy transfer
d. Biotic communities
Answer:
a. Gradual, fairly changes and pH development of a given area

Question 23.
Succession occur in which area ?
Answer:
Flooded, earthquake and anthropogenic area

Question 24.
Plant succession in saline water is…………
Answer:
Halosere

Question 25.
The replacement of existing community by other factors like soil erosion, leaching etc. is …………..
Answer:
Allogenic succession.

Question 26.
The type of succession takes less time to the time taken for primary succession ?
Answer:
Secondary succession

Question 27.
The type of succession in which organisms like bacteria, fungi, actinomycetes and animals are dominant during its early stages is …………..
a. Heterotrophic
b. Allogenic
c. Autotrophic
d. Autogenic
Answer:
a. Heterotrophic

Question 28.
Match the following:

a. A – iv), B – iii), C – ii), D – i)
b. A – i), B – ii), C – iii), D – iv)
c. A – ii), B – iii), C – iv), D – i)
d. A – iii), B – ii), C – i), D – iv)
Answer:
a. A – iv), B – iii), C – ii), D-i)

Question 29.
Pioneer community like blue green algae, green algae, diatoms, bacteria etc are present in ……….. stage of hydrosere.
Answer:
Phytoplankton stage

Question 30.
Rooted floating plants like Nelumbo Nymphaea and Trapa and free floating SPS wolffia and lemna are present in this stage is
Answer:
Submerged free floating stage

Question 31.
Submerged hydrophytes like char a, utricularia, vallisneria, hydrilla are present in the ………… stage of hydrosere.
Answer:
Submerged plant.

Question 32.
Mat – like vegetation with the help of much branched root system is the character of ………….. stage of hydrosere
Answer:
Marsh meadow.

Question 33.
Species of cyperaceae and poaceae like carex, juncus cyperus and eleocharis colonise in this i area is
Answer:
Marsh meadow stage

Question 34.
Salix and cornus (shrubs) and trees like populous and alnus are present in the …………… stage.
Answer:
Shrub stage

Question 35.
Say true or false
Reduce, reuse, recycle are “three R” s for waste management.
Answer:
True

Question 36.
…………… is the best example for urban eco restoration in the state of Tamilnadu.
Answer:
Urban ecosystem restoration model.

Question 37.
Initiation of plant succession on barren rock is …………………
Answer:
Lithosere

Question 38.
Succession with minimal amount of water is
a. Merosere
b. Psammosere
c. Halosere
d. Xerosere
Answer:
d. Xerosere

Question 39.
Succession in a fresh water ecosystem is
a. Merosere
b. Hydrosere
c. Lithosere
d. Halosere
Answer:
b. Hydrosere

Question 40.
Study of interaction between living and non- living components is
a. Biomass
b. Food chain
c. Food web
d. Ecosystem
Answer:
d. Ecosystem

Question 41.
Which of the following is not related to photosynthetic active radiation.
a. 400-700 nm
b. 10% is held by ozone
c. 2-10% by green plants
d. 46% reaches earth surface
Answer:
d. 46% reaches earth surface

Question 42.
Which of the following light is efficient for
photo-synthesis.
a. Blue and red
b. Blue and green
c. Blue and white
d. Blue and violet
Answer:
a. Blue and red

Question 43.
Which of the following determine the productivity of different ecosystem.
a. Fixation of radiant energy
b. Population
c. Size of ecosystem
d. Number of plants
Answer:
a. Fixation of radiant energy

Question 44.
Which is the right representation of detritus food chain?
a. Grass Earthworm → Black bird → Hawk
b. Grass Mouse → Snake Eagle
c. Fallen leaves → Earthworm → Black bird →Hawk
d. Plants → Rabbit → Snake → Eagle
Answer:
c. Fallen leaves → Earthworm → Black bird →Hawk

Question 45.
NPP of whole biosphere is estimated to be …………. about billion tons dry weight/year
a. 140
b. 170
c. 150
d.160
Answer:
b. 170

Question 46.
NPP of oceanic producers is only ……………… billiob tons/year in unit time.
a. 55
b. 45
c. 56
d. 54
Answer:
a. 55

Question 47.
During energy transfer from one trophic level to other only 10% stored at every level this is related to
a. First law of thermodynamics
b. Second law of thermodynamics
c. Ten percent law
d. Law of thermodynamics
Answer:
c. Ten percent law

Question 48.
The commonly occurring pioneer species in
xerich succession
a. Lichens
b. Mosses
c. Bryophytes
d. Pteridophytes
Answer:
a. Lichens

Question 49.
Lowest productivity is seen in
a. Ocean
b. Grass land
c. forest
d. savannah
Answer:
a. Ocean

Question 50.
The term biosphere is used for
a. Ecosystem
b. Plants and animals
c. All living organism
d. The part of the earth with life
Answer:
d. The part of the earth with life

Question 51.
Bio geo chemical cycle refers to
a. Cycling of nutrients
b. Cycling of nutrients with ecosystem
c. Water cycle
d. Cycling of chemicals substrances
Answer:
b. Cycling of nutrients with ecosystem

Question 52.
Which of the following does not contain phosphorous?
a. Phospholipids
b. DNA, RNA
c. ATP, NADP
d. Respiration
Answer:
d. Respiration

Question 53.
The ecosystem with (or) without human interference is
a. Terrestrial
b. Natural
c. Artificial
d. Lotic
Answer:
b. Natural

Question 54.
Examine the ecological pyramid given below and select the type of it represent

a. Upright pyramid of biomass
b. Upright pyramid of number
c. Inverted pyramid of biomass
d. Inverted pyramid of number
Answer:
a. Upright pyramid of biomass

Question 55.
The organisms which eat both plants and animals are called ……………….
Answer:
Omnivores

Question 56.
When sparrow eats insects and worms it is a
a. Primary consumer
b. Secondary consumer
c. Tertiary consumer
d. Carnivore
Answer:
b. Secondary consumer

Question 57.
Imagine number of fruit eating birds and insects feeding or a big tree what kind of pyramid would be ?
a. Inverted pyramid of number
b. Inverted pyramid of energy
c. Upright pyramid
d. Upright pyramid of energy
Answer:
a. Inverted pyramid of number

Question 58.
Which of the following is natural ecosystem.
a. Pond and lake
b. Rice field
c. Maize fi eld
d. Aquarium
Answer:
a. Pond and lake

Question 59.
Which one of the following food chain refers inverted pyrmid? Q23D
a. Grasses → Rats → Snake → Hawk
b. Banyan tree → Birds → Beetles → Fungi
c. Phytoplanktons → Zooplanktons → Fishes → snakes
d. Plants Rabbits → Fox → Hawk
Answer:
c. Phytoplanktons → Zooplanktons → Fishes → snakes

Question 60.
The quantity of energy present in the universe is constant it is related to
a. Second law of thermodynamics
b. First law of thermodynamics
c. Ten percent lawd. Law of thermodynamics
Answer:
b. First law of thermodynamics

II. Two Marks

Question 1.
What do you mean standing quality (or) Standing state of abiotic components ?
Answer:

• Abiotic components play vital role in an ecosystem.
• The total inorganic substances present in any ecosystem at a given time is called standing quality (or) standing state.

Question 2.
In most of the ecosystem, which one is called autotrophs why?
Answer:

• Autotrophs are organism which can manufacture the organic compounds from simple inorganic components through a process called photo synthesis.
• Eg. Green plants. They are called as producers.

Question 3.
What is standing crop?
Answer:

• The amount of living materials present in a population at a given time is known as standing crop.
• Which is expressed in terms of number (or) biomass per unit area.

Question 4.
What are the functions of an ecosystem?
Answer:

• Its functions are energy creation and sharing of energy.
• It is the way to cycling of materials between the living and nonliving component of the ecosystem.

Question 5.
Why biomass production is called productivity of an ecosystem?
Answer:

• The rate of biomass production per unit area in a unit time is called productivity.
• It can be expressed in terms of gm / m2 / yr (or) kcal / m2 / yr

Question 6.
What is biomass? How it is measured?
Answer:

• The total quantity (or) weight of organism in a give area is called biomass.
• It can be measured as fresh weight (or) dry weight (or) carbon weight of organisms.

Question 7.
Write the difference between gross primary productivity and gross secondary productivity ?
Answer:
Grass Primary Productivity :

1. The total amount of food energy (or) biomass produced in an ecosystem
2. It is done by autotrophs through the process called photosynthesis

Grass Secondary Productivity :

1. The total amount of plant material ingested minus (-) materials lost as faeces.
2. It is done by herbivores by the process called ingestion.

Question 8.
Differentiate net primary productivity from net secondary productivity ?
Answer:
Net Primary Productivity :

1. The proportion of energy which remains after respiration loss in the plant.
2. Net primary productivity is calculated in producers.

Net Secondary Productivity:

1. Stored energy (or) biomass per unit area per unit time after respiratory loss.
2. Net secondary productivity is calculated in consumers.

Question 10.
Which factors may affect the primary productivity of plants (or) producers ?
Answer:
Primary productivity of plants affected by

• Plant species of an area.
• Photosynthetic capacity
• Availability of nutrients
• Solar radiation
• Precipitation
• Soil type
• opographic factors
• Environmental factors.

Question 11.
How does NPP calculated from GPP?
Answer:

• NPP = GPP – Respiration
• Thus it is the difference between gross primary productivity and respiration is net primary productivity.

Question 12.
Why grey carbon different from brown carbon?
Answer:

• Grey carbon is stored in fossil fuel like coal, oil and biogas deposits in the lithosphere
• Brown carbon is stored in industrialized forest wood used in making commercial articles.

Question 13.
What are the sources for blue carbon and black carbon
Answer:

• Blue carbon is stored in the atmosphere.
• Black carbon is emitted from diesel engine gas and coal fired power plants.

Question 14.
What is energy flow ?
Answer:

• The transfer of energy in an ecosystem between trophic levels can be termed as energy flow.
• It is the key function in an ecosystem.

Question 15.
If crow is absent in an ecosystem what would happen?
Answer:

• The crow has omnivorous type of Nutrition.
• They eat cereals, fruit and seeds, small insects and worms.
• They eat dead & decaying animals body and keep the environment clean, so known as scavengers of the sky.
• They occupy several trophic levels in the food chain.
• When they eat some fruits they swallow the seeds which are dispersed along with the excreta.
• However unlike certain pollination and insects they are not considered vital organisms because their loss from the ecu system mav cause drastic impacts, leading to the extinction of rhe. it partk ular plant species which can’t be pollinated in the absence of the particular insect/bird.
• However when crow is absent, then its niche in the food chain will be kept vacant ecological, this will be drastic change occur some other organism mav evolve to occupy the same neche in the long run.

Question 17.
Conversion of light energy into chemical energy which law is related to this ?
Answer:

The first law of thermodynamics is related to this statement.

Question 18.
Construct the diagrammatic representation of grazing food chain.
Answer:

Question 19.
Draw the diagrammatic representation of detritus food chain.
Answer:

Question 20.
Food web is known as basic unit of ecosystem. Why ?
Answer:

• The interlocking pattern of a number of food chain form a weblike arrangement called food web.
• It is known as basic unit of ecosystem to maintain its stability in nature.
• It is called homeostasis.

Question 21.
Why ecological pyramids are called Eltonianpyramids ?
Answer:

• The concept of ecological pyramids was introduced by Charles Elton in the year 1927.
• Thus ecological pyramids are called Eltonian pyramids.

Question 22.
What is ecological pyramid ?
Answer:
Graphic representation of the trophic structure and function at successive trophic levels of an ecosystem is called ecological pyramid.

Question 23.
Why the pyramids of energy is always upright?
Answer:

• There is a gradual decrease in energy transfer at successive tropic levels from producers to the upper levels.
• Therefore, the pyramid of energy is always upright.

Question 24.
Define pyramid of energy.
Answer:
The graphical representation of energy flow of each successive trophic level in an ecosystem is called pyramids of energy.

Question 25.
Name the process which is essential for recycling and balancing the nutrient in an ecosystem?
Answer:
Decomposition is a process in which the detritus are breakdown into simple organic matter by the decomposers.

Question 26.
Write the difference between limnology and oceanography ?
Answer:
Limnology
It is the studv of biological, chemical physical and geological components of inland fresh water aquatic ecosystem (ponds, lakes etc)

Oceanography :
It is the study of biological, chemical, physica I and geological components of ocean.

Question 27.
Blue carbon ecosystems are very important to nature. Why?
Answer:

• Sea grasses and mangroves of estuarine and coastal ecosystems are the most efficient in carbon sequestration.
• Hence these ecosystems are called blue carbon ecosystem.

Question 28.
What is carbon sequestration?
Answer:
Carbon sequestration is the process of capturing and storing carbondioxide from the atmosphere in carbon sinks such as ocean and forest.

Question 29.
Odd one out and give reason.
Answer:
Provision of habitat, nutrient recycling, primary production, succession Odd one out: Succession.
Reason : Replacement of one type of plant community by other of the same place is known as succession. While others are supporting services of ecosystem services.

Question 30.
Odd one out and give reason.
Lichen, blue green algae, green algae diatoms, bacteria.
Answer:
Odd one out: Lichen
Reason : Lichen is related to primary succession. While others are related to phytoplankton stage of hydrosere.

Question 31.
Write the slogan for the safety of the environment.
Answer:
“Use Ecosystem. But don’t lost ecosystem. Make it sustainable.”

Question 32.
Define fragmentation.
Answer:
The breaking down of detritus in to smaller particles by detritivores like bacteria, fungi and earth worm is known as Fragmentation.

Question 33.
What is Humification?
Answer:
It is a process by which simplified detritus is changed into dark coloured amorphous substance called humus.

Question 34.
Define oceanography.
Answer:
It is the study of biological chemical, physical and geogical components of ocean.

Question 35.
In different food chains of different ecosystem the placement of man is not mentioned. You give placement in a suitable food chain and give reason for your answer.
Answer:

• Placement of man in the food chain is not clear, due to the various dietary choices of each human.
• Many are omnivores – consuming both plants & meat.
• They may be kept on the 3rd or even on the 4th trophic level.
• Meat eaters (cow, goat are herbivores) are a part of 3rd trophic level.
• If you were to eat Salmon, – Salmon consume other fish – and so you are in the 4th trophic

III. Three Marks

Question 1.
What is photosynthetically active radiation ?
Answer:

• The amount of light available for photosynthesis of plants is called photosynthetically active radiation.
• Which is between the range of 400 – 700 nm of wave length.
• Generally plants absorb move blue and red light for efficient photosynthesis.
• Only 2 -10% of the solar energy is used by green plants for photosynthesis.

Question 2.
Differentiate green carbon from grey carbon.
Answer:
Green Carbon :

1. It is the carbon stored in the biosphere.
2. It is done by the process of photosynthesis by green plants.

Grey Carbon :

1. It is the carbon stored in fossil fuel. (Coal, oil, biogas)
2. It is done by the process of decomposition in the lithosphere.

Question 3.
Differentiate primary productivity from secondary productivity.
Answer:

Question 4.
“The energy transformation results in the education of the free energy of the system”. What does it states ?
Answer:

• It states second law of thermodynamics.
• Usually energy transformation cannot be 100% efficient.
• As energy is transformed from one organism to another in the form of food, where as a large part of energy is dissipated as heat through respiration. (Eg.) Ten percent law.

Question 5.
What is ten percent law?
Answer:

• This law was proposed by Lindeman (1942)
• During transfer of food energy from one trophic level to other, only about 10% stored at every level and rest of them 90% is lost in respiration, decomposition in the form of heat.
• Hence the law is called ten percent law.

Question 6.
Which type of food chain is present in all ecosystem ? (or) What is detritus food chain?
Answer:

• It begins with dead organic matter.
  Which is an important source of energy
• Transfer of energy from Detritus → Detritivores → Small carnivores → Top carnivores
• This type of food chain is present in all ecosystems.

Question 7.
Complete the missing organisms of food web in grassland ecosystem.
Answer:

1. A – Rabbit
2. B – Mouse
3. C – Lizard
   

Question 8.
What are the importance of studying food web ? (or) What are significant of food web? Is there any significance in maintaining food web?
Answer:

• Food web is constructed to describe species interaction called direct interaction.
• It can be used to illustrate indirect interaction among different species.
• It can be used to reveal different patterns of energy transfer in terrestrial and aquatic ecosystems.

Question 9.
What are the different shapes of pyramids present in pyramids of number?
Answer:

• There are three different shapes of pyramids present in pyramid of number.
• Pyramid of number in grassland and pond ecosystem are always upright in shape.
• In forest ecosystem it is spindle shaped.
• In parasite ecosystem it is inverted.

Question 10.
What are the different shapes of pyramids present in pyramid of biomass?
Answer:
According to pyramid of biomass
Eco System – Shape :
Grassland and forest – Upright
Pond ecosystem – Inverted

Question 11.
Why pyramids of biomass in grass land and forest ecosystem is always upright ?
Answer:

• In grassland and forest there is a gradual decrease in biomass of organisms from producers to top carnivore.
• There fore it is always upright.

Question 12.
Why pyramids of biomass in pond ecosystem is always inverted in shape?
Answer:

• In pond ecosystem the bottom of the pyramid is occupied by the producers which are small organisms posses least biomass.
• So the value gradually increases towards the tip of the pyramid.
• Therefore pyramid of biomass is always inverted in shape.

Question 13.
Differentiate humification and mineralisation.
Answer:
Humification :

1. It is the process by which simplified detritus into dark coloured amorphous substance called humus.
2. Humus is resistant to microbial action.

Mineralisation :

1. Release of inorganic nutrients from the humus is called mineralisation.
2. Some microbes are involved in release of nutrients.

Question 14.
Define catabolism:
Answer:
The decomposers produce some extracellular enzymes in their surroundings to break down complex organic and inorganic compounds into simpler ones called catabolism.

Question 15.
What is leaching or eluviation ? (or) Which process of decomposition helpful to enrich lower layer of soil ?
Answer:
The movement of decomposed water soluble organic and inorganic compounds from the surface to the lower layer of soil by water is called eluviation (or) leaching.

Question 16.
What is bio-geo chemical cycle ?
Answer:
Circulation of nutrients within the ecosystem (or) biosphere is known as biogeo chemical cycles, (or) Cycling of materials.

Question 17.
Which cycles are called sedimentary cycles ? Why?
Answer:

• Phosphorus, sulphur, calcium are called as sedimentary cycles.
• Which are present as sediments on earth.
• Sedimentary cycles are very slow its take a long time to complete its circulation, because nutrient elements may get locked in the reservoir pool.

Question 18.
Wihat is carbon cycle?
Answer:

• The circulation of carbon between organisms and environment is known as carbon cycle.
• Cycling of carbon between organisms and atmosphere is consequence (event) of two reciprocal process of photosynthesis and respiration.

Question 19.
What is ecosystem resilience ? (or) Ecosystem robustness?
Answer:
Ecosystem is damaged by disturbances from fire, flood, predation, infection, drought, etc., removing a great amount of biomass. However, ecosystem is endowed with the ability to resist the damage and recover quickly. This ability of ecosystem is called ecosystem resilience or ecosystem robustness.

Question 20.
What are the ways to go green and save green?
Answer:

• Close the tap when not in use.
• Switch off the electrical gadgets when not in use.
• Never use plastics and replace them with biodegradable products.
• Always use ecofriendly technology and products.

Question 21.
Draw and write the 3 Rs for the safety and benefits of the environment.
Answer:

The three R’s are – reduce, reuse and recycle. It refers to the changing of one’s lifestyle for the safety and benefits of the environments (Reduce, Reuse, Recycle)

Question 22.
Which is significance of food web?
Answer:

• Food web is constructed to describe species interaction called direct interaction
• It can be used to illustrate indirect interaction among different species.
• It can be used to study bottom up or top down control of community structure.
• It can be used to reveal different patterns of energy transfer in terrestrial and aquatic ecosystems.

Question 23.
What are the types of carbon?
Answer:

1. Green carbon : carbon stored in the biosphere by the process of photosynthesis.
2. ray carbon: carbon stored in fossil fuel (Coal, oil and biogas deposits in the lithosphere).
3. Blue carbon : carbon stored in the atmosphere and oceans.
4. Brown carbon: carbon stored in industrialized forests (wood used in making commercial articles)
5. Black carbon : carbon emitted from gas, diesel engine and coal fired power plants.

IV. Five Marks

Question 1.
Define ecosystem. Describe the components of ecosystem
Answer:
The term ecosystem was proposed by A.G. Tansley (1935), who defined it as.

• The system resulting from the integration of all the living and non living factors of the environment.
  Whereas Odum (1962) defined ecosystem as
• Eco system is structural and functional unit of ecology.
• Ecosystem comprises of two major components
  i) Abiotic ii) Biotic components

i) Abiotic (non-living) components:
Edaphic Factors – Soil, air, soil water and pH of soil.
Topography factors – Latitude altitude Organic components – Carbohydrates, protein’s lipids and humic substances

Inorganic substances:
C, H, O, N and P . Abiotic components play vital role in any ecosystem hence it is important for standing quality.

ii) Biotic (living) components:
It includes all living organisms like plants, animal, fungi and bacteria.

• They form the trophic structures of any ecosystem.
• It has two components
  i) Autotrophic components ii) Heterotrophic components

i) Autotrophic components:
Autotrophs are plants (or) producers which can manufacture the organic compounds from simple inorganic components through a process called photosynthesis.

ii) Heterotrophic components:
Heterotrophs are organisms which consume the producers are called consumers. They are two types
i) Macro consumers ii) Micro consumers

• Macro consumers are herbivores, carnivores and omnivores.
• Micro consumers are called decomposers. (Eg.) Bacteria, actinomycetes and fungi
• Biotic components are essential to construct the food chain, food web and ecological pyramids.

Question 2.
What kind of solar radiation is used in photosynthesis ? (OR)
AR is not always constant because of clouds, tree shades, air, dust particles, seasons latitudes and length of the daylight availability. (OR)
What is photosynthetically active radiation ? (OR)
How it is calculated for active photosynthesis in plants ? (OR)
From the sunlight, only 2-10% of the solar energy is used by green plants for photosynthesis. Explain why?
Answer:

• The amount of light available for photosynthesis of plants is called photosynthetically active radiation.
• Which is between the range of 400 -700 nm wavelength. Which is essential for photosynthesis and plant growth.
• Generally plants absorb more blue and red light for efficient photosynthesis.
• Of the total sunlight, 34 percent that reaching the atmosphere is reflected back into the atmosphere, moreover 10% is held by ozone.
• Remaining 56% reaches the earths surface out of this 56%, only 2 – 10% of solar energy is used by green plants for photosynthesis while the remaining portion is dissipated as heat
• PAR is generally reported as millimoles / square meter / second by using silicon photo voltic detector.
• Which detect only 400 – 700 nm wavelength of light.
• PAR values range from 0 to 3000 millimoles / square meter / second.
• At night PAR is zero and during midday in summer, PAR often reaches 2000 – 3000 millimoles /square meter / second.

Question 3.
What is primary productivity ? What are its types ? What are the factors affecting primary productivity ? (or)
What is primary productivity ? How net primary productivity is calculated ? What are the factors affecting primary productivity.
Answer:
1.Primary productivity:
The chemical energy or organic matter generated by autotrophs during the process of photosynthesis and chemosynthesis is called primary productivity. It is the source of energy for all organisms, from bacteria to human.

a. Gross Primary Productivity (GPP):
The total amount of food energy or organic matter or biomass produced in an ecosystem by autotrophs through the process of photosynthesis is called gross primary pro-ductivity

b. Net Primary Productivity (NPP):
The proportion of energy which remains after respiration loss in the plant is called net primary productivity. It is also called as apparent photosynthesis. Thus the difference between GPP and respiration is known as NPP.
NPP = GPP – Respiration
NPP of whole biosphere is estimated to be
about 170 billion tons (dry weight) per year. Out of which NPP of oceanic producers is only 55 billion tons per year in unit time.

Factors affecting primary productivity:

• Factors affecting primary productivity depends upon the plant species of an area
• Their photosynthetic capacity, availability of nutrients solar radiation, precipitation, soil type and other environmental factors.
• It varies in different types of ecosystems.

Question 4.
What is secondary productivity and its types ? In what way community productivity calculated ?
Answer:
Secondary productivity:
The amount of energy stored in the tissues of heterotrophs or consumers is called secondary productivity.

a. Gross secondary productivity:
It is equivalent to the total amount of plant material is ingested by the herbivores minus the materials lost as faeces.

b. Net secondary productivity:
Storage of energy or biomass by consumers per unit area per unit time, after respiratory loss is called net secondary productivity.

Community productivity:
The rate of net synthesis of organic matter (biomass) by a group of plants per unit area per unit time is known as community productivity.

Question 5.
How does energy flow in an ecosystem, (or)
Describe about the concept of trophic level in an ecosystem, (or)
Write about various trophic level of food chain in an ecosystem.
Answer:

• A trophic level refers to the position of an organism in the food chain.
• The number of trophic levels is equal to the number of steps in the food chain.
• The green plants (producers) occupying the first trophic level (TA are called producers.
• The energy produced by the producers is utilized by the plant eaters (herbivores) they are called primary consumers and occupies the second trophic level (T₂).
• Herbivores are eaten by carnivores, which occupy the third trophic level (T₃).
  They are also called secondary consumers or primary carnivores.
• Carnivores are eaten by the other carnivores, which occupy the fourth trophic level (T₄). They are called the tertiary consumers or secondary carnivores.
• Some organisms which eat both plants and animals are called as omnivores (Crow). Such organisms may occupy more than one trophic level in the food chain.

Question 6.
How does the laws of thermodynamics explain the storage and loss of energy in an ecosystem ? (or) Write about laws of thermodynamics in an ecosystem.
Answer:
Laws of thermodynamics:
The storage and loss of energy in an ecosystem is based on two basic laws of thermodynamics.

i) First law of thermodynamics

• It states that energy can be transmitted from one system to another in various forms. Energy cannot be destroyed or created.
• As a result, the quantity of energy present in the universe is constant.
• Example: In photosynthesis, the product of starch (chemical energy) is formed by the combination of reactants (chlorophyll, H₂O, CO₂). ‘ “
  Starch is acquired from the external sources (light energy) and so there is no gain or loss in total energy. Here light energy is converted into chemical energy.
  
• Light energyv → Chemical energy

ii) Second law of thermodynamics Usually energy transformation cannot be 100% efficient. As energy is transferred from one organism to another in the form of food, a portion of it is stored as energy in living tissue, whereas a large part of energy is dissipated as heat through respiration. Example: Ten percent law Ten percent law : During transfer of food energy from one trophic level to other, only about 10% stored at every level and rest of them (90%) is lost in respiration, decomposition and in the form of heat. Hence, the law is called ten percent law.

Question 7.
What is food chain ? (or) How does movement takes place from producers to top carnivore? What are its types.
Answer:

• The movement of energy from producers upto top carnivores is known as food chain,
• Generally, there are two types of food chain, (1) Grazing food chain and (2) Detritus food chain.

1. Grazing food chain : Main source of energy for the grazing food chain is the Sun. It begins with the first link, producers (plants) The second link in the food chain is primary consumers (mouse) which get their food from producers. The third link in the food chain is secondary consumers (snake) which get their food from primary consumers. Fourth link in the food chain is tertiary consumers (eagle) which get their food from secondary consumers.

2. Detritus food chain : This type of food chain begins with dead organic matter which is an important source of energv. A large amount of organic matter is derived from the dead plants, animals and their excreta. This type of food chain is present in all ecosystems.

The transfer of energy from the dead organic matter, is transferred through a series of organisms called detritus consumers (detritivores)- small carnivores – large (top) carnivores with repeated eating and being eaten respectively. This is called the detritus food chain.

Question 8.
What is ecological pyramid ? Write about ecological pyramid of number.
Answer:
Graphic representation of trophic structure and function in successive trophic levels of an ecosystem is called ecological pyramid (or) Eltonian pyramid.

Figure 7.8 : Pyramids of numbers (individuals per unit area) in different types of ecosystems, Upright – A) Grassland ecosystem B) Pond ecosystem, Spindle shaped – C) Forest ecosystem,
Inverted – D) Parasite ecosystem

Pyramid of number:

• A graphical representation of the number of organism present at each successive trophic level in an ecosystem is called pyramid of number.
• There are different shapes, pyramid of number in grassland and pond ecosystem are always upright. Because
• There is a gradual decrease in number of organisms in each trophic level from Producer → Primary consumer then → Secondary consumer and finally → Tertiary consumer.
• Pyramid of number in forest ecosystem looks spindle shaped. Because
• In forest ecosystem, large sized tree (producer) which are lesser in number, herbivores are more in number than produces.
• In final tertiary consumers are lesser in number than the secondary consumer.
• In a parasite ecosystem the pyramid of number is always inverted because
• Its starts with single tree, there is gradual increase in the number of organisms in successive
  trophic levels from producers to tertiary consumers.
• Question 9.
  Write about the mechanism of decomposition ? What are the factors affecting decomposition, (or) Describe about an essential process for recycling and balancing the nutrient pool in an ecosystem.
  Answer:

• Decomposition is a step wise process of degradation mediated by enzymatic reactions. Detritus acts as a raw material for decomposition.
• a. Fragmentation – The breaking down of detritus into smaller particles by detritivores like bacteria, fungi and earth worm is known as fragmentation.
• b. Catabolism – The decomposers produce some extracellular enzymes in their surroundings to break down complex organic and inorganic compounds in to simpler ones. This is called catabolism
• c. Leaching or Eluviation – The movement of decomposed, water soluble organic and inorganic compounds from the surface to the lower layer of soil or the carrying away of the same by water is called leaching or eluviation.
• d. Humification – Detritus is changed into dark coloured amorphous substance called humus. It is highly resistant to microbial action, therefore decomposition is very slow.
• e. Mineralisation – The release of inorganic nutrients from the humus is called mineralisation.
• Decomposition is affected by climatic factors like temperature, soil moisture, soil pH oxygen and also the chemical quality of detritus.

Question 10.
Define pyramid of biomass. What are its types based on shape ?
Answer:

• A graphical representation of the amount of organic material (biomass) present at each successive trophic level in an ecosystem is called pyramid of biomass.
• In grassland and forest ecosystems, there is a gradual decrease in biomass of organisms at successive trophic levels from producers to top carnivores (Tertiary consumer). Therefore, these two ecosystems show pyramids as upright pyramids of biomass.
• However, in pond ecosystem, the bottom of the pyramid is occupied by the producers, which comprise very small organisms possessing the least biomass and so, the value gradually increases towards the tip of the pyramid. Therefore, the pyramid of biomass is always inverted in shape.

Figure 7.9: Pyramids of biomass (dry weight per unit area) in different types of ecosystems.
Upright – A) Grassland ecosystem Inverted – C) Pond ecosystem

Question 11.
Write about the structure of pond ecosystem with diagram.
Answer:

• Pond ecosystem is a self sustaining and self regulatory fresh water ecosystem, which shows a complex interaction between the abiotic and biotic components in it.
• A pond ecosystem consists of dissolved inorganic (CO₂, O₂, Ca, N, Phosphate) and organic substances (amino acids and humic acid) formed from the dead organic matter.
• The function of pond ecosystem is regulated by few factors like the amount of light, temperature, pH value of water and other climatic conditions.
• Biotic components : They constitute the producers, variety of consumers and decomposers (microorganisms).
• A variety of phytoplankton like Oscillatoria, Anabaena, Eudorina, Volvox and Diatoms. Filamentous algae, floating plants, rooted floating plants are the major producers of a pond ecosystem.
• zooplanktons, benthos, secondary consumers like water beetles and frogs tertiary consumers (carnivores) like duck, crane and some top carnivores which include large fish, hawk ,man, etc.
• They are also called as microconsumers. They help to recycle the nutrients in the ecosystem.
• The cycling of nutrients between abiotic and biotic components is evident in the pond ecosystem, making itself self sufficient and self regulating.

Question 12.
Write important features of a sedimentation cycle in an ecosystem.
Answer:
Sedimentary cycles are very slow. They take a long time to complete their circulation. Because during recycling, nutrient elements may get locked in the reservoir pool there by taking a very long to come out and continue circulation.

• It is a type of sedimentary cycle. Already we know that phosphorus is found in the biomolecules like DNA, RNA, ATP, NADP and phospholipid molecules of living organisms.
• Bulk quantity of phosphorus is present in rock deposits, marine sediments and guano.
  It is released from these deposits by weathering process.
• The producers absorb phosphorus in the form of phosphate ions, and then it is transferred to each trophic level of food chain through food.
• Again death of the organisms and degradation by the action of decomposers, the phosphorus is released back into the lithosphere and hydrosphere to maintain phosphorus cycle.

Question 13.
Based on the varieties of benefits obtained from ecosystem what are the various types ecosystem services ?
Answer:
The varieties of benefits obtained from the ecosystem are generally categorized into the follo wing four types

Question 14.
Discuss about the various benefits of mangrove ecosystem services, (or) What are the various benefits of mangrove ecosystem services to nature and human being?
Answer:
Mangrove ecosystem services:

• Offers habitat and act as nursery for aquatic plants and animals Provides medicine, fuel wood and timber.
• Act as bridge between sea and rivers by balancing sedimentation and soil erosion.
• Help to reduce water force during cyclones, tsunamis and high tide periods.
• Help in wind break, O₂ production, carbon sequestration and prevents salt spray from waves.

Question 15.
If we fail to protect environment, we will fail to save posterity? (or) What are the practices we have to follow to protect the ecosystem ? (or) How to protect the ecosystem ?
Answer:
To protect ecosystem, we have to practice the following in our daily life.

• Buy and use only ecofriendly products and recycle them.
• Grow more trees.
• Choose sustained farm products (vegetables, fruits, greens, etc.)
• Reduce the use of natural resources.
• Recycle the waste and reduce the amount of waste you produce.
• educe consumption of water and electricity.
• Reduce or eliminate the use of house-hold chemicals and pesticides.
• Maintain your cars and vehicles properly. (In order to reduce carbon emission)
  Create awareness and educate about ecosystem protection among your friends and family members and ask them to find out solution to minimise this problem.

Question 16.
What are the strategy of ecosystem management ?
Answer:
Strategy of ecosystem management:

• It is used to maintain biodiversity of ecosystems.
• It helps in indicating the damaged ecosystem (Some species indicate the health of the ecosystem: such species are called a flagship species).
• It is used to recognize unavoidance of ecosystem change and plan accordingly.
• It is one of the tools used for achieving sustainability of ecosystem through sustainable development programme (or projects).
• It is also helpful in identifying ecosystems which are in need of rehabilitation.

Question 17.
What are various steps involved in ecological succession ? (or) What are the characteristics of ecological succession ?
Answer:
Characteristics of ecological succession:

• It is a systematic process which causes changes in specific structure of plant community.
• It is resultant of changes of abiotic and biotic factors.
• It transforms unstable community into a stable community.
• Gradual progression in species diversity, total biomass, niche specialisation, and humus content of soil takes place.
• It progresses from simple food chain to complex food web.
• It modifies the lower and simple life form to the higher life forms.
• It creates inter-dependence of plants and animals.

Question 18.
Tabulate the differences between primary and secondary succession?
Answer:

Question 19.
Write about the different stages of hydrosere? (or) Write about the different substages of hydrosere in plant succession.
Answer:
The type of succession is hydrosere. It includes the following stages.

1. Phytoplankton stage
2. Submerged plant stage
3. Submerged free floating stage
4. Reed-swamp stage
5. Marsh rnedow stage
6. Shr ub stage
7. Forest stage

1. Phytoplankton stage:
It is the first stage of succession consisting of the pioneer community like blue green algae, green algae, diatoms, bacteria, etc., The colonization of these organisms enrich the amount of organic matter and nutrients of pond due to their life activities and death. This favours the development of the next serai stages.

2. Submerged plant stage:
As the result of death and decomposition of planktons, silt brought from land by rain water, lead to a loose mud formation at the bottom of the pond. Hence, the rooted submerged hydrophytes begin to appear on the new substratum. Example: Chara, Utricularia. The death and decay of these plants will build up the substratum of pond to become shallow. Therefore, this habitat now replaces another group of plants which are of floating type.

3. Submerged free floating stage:
During this stage, the depth of the pond will become almost 2-5 feet. Hence, the rooted hydrophytic plants and with floating large leaves start colonising the pond. Example: Rooted floating plants like Nelumbo, Nymphaea and Trapa. By death and decomposition of these plants, further the pond becomes more shallow. Due to this reason, floating plant species is gradually replaced by another species which makes new serai stage.

4. Reed-swamp stage:
It is also called an amphibious stage. During this stage, rooted floating plants are replaced by plants which can live successfully in aquatic as well as aerial environment. Example: Typha

5. Marsh meadow stage:
When the pond becomes swallowed due to decreasing water level, species of Cyperaceae and Poaceae. They form a mat-like vegetation with the help of their much branched root system. This leads to an absorption and loss of large quantity of water. At the end of this stage, the soil becomes dry and the marshy vegetation disappears gradually and leads to shurb stage.

6. Shrub stage:
As the disappearance of marshy vegetation continues, soil becomes dry. Hence, these areas are now invaded by terrestrial plants like shrubs (Salix and Cornus) and trees (Populus and Alnus). These plants absorb large quantity of water and make the habitat dry. Further, the accumulation of humus with a rich flora of microorganisms produce minerals in the soil, ultimately favouring the arrival of new tree species in the area.

7. Forest stage:
It is the climax community of hydrosere. A variety of trees invade the area and develop any one of the diverse type of vegetation. Example: Temperate mixed forest 207

Question 20.
Write about the significance of plant succession.
Answer:
Significance of Plant Succession:

• Succession is a dynamic process. Hence an ecologist can access and study the serai stages of a plant community found in a particular area.
• The knowledge of ecological succession helps to understand the controlled growth of one or more species in a forest.
• Utilizing the knowledge of succession, even dams can be protected by preventing siltation
• It gives information about the techniques to be used during reforestation and afforestation.
• It helps in the maintenance of pastures.
• Plant succession helps to maintain species diversity in an ecosystem.
• Patterns of diversity during succession are influenced by resource availability and disturbance by various factors.
• Primary succession involves the colonization of habitat of an area devoid of life.
• Secondary succession involves the reestablishment of a plant community in disturbed area or habitat.
• Forests and vegetation that we come across all over the world are the result of plant succession.

Question 21.
What is carbon cycle ? Draw the diagrammatic sketch showing carbon cycle ?
Answer:
The circulation of carbon between organisms and environment is known as the carbon cycle

Tamilnadu State Board New Syllabus Samacheer Kalvi 12th Bio Botany Guide Pdf Chapter 6 Principles of Ecology Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 12th Bio Botany Solutions Chapter 6 Principles of Ecology

12th Bio Botany Guide Principles of Ecology Text Book Back Questions and Answers

I. Choose the correct evaluation

Question 1.
Arrange the correct sequence of ecological hierarchy starting from lower to higher level.
a. Individual organism → Population Landscape → Ecosystem
b. Landscape → Ecosystem → Biome → Biosphere
c. Community → Ecosystem → Landscape → Biome
d; Population → organism → Biome → Landscape
Answer:
c. Community → Ecosystem → Landscape → Biome

Question 2.
Ecology is the study of an individual species is called
i) Community ecology
ii) Autecology
iii) Species ecology
iv) Synecology
a. i only
b. ii only
c. i and iv only
d. ii and iii only
Answer:
d. ii and iii only

Question 3.
A specific place in an ecosystem, where an organism lives and performs its functions is
a. habitat
b. niche
c. landscape
d. biome
Answer:
b. niche

Question 4.
Read the given statements and select the correct option.
i) Hydrophytes possess aerenchyma to support themselves in water.
ii) Seeds of Viscum are positively photoblastic as they germinate only in presence of light.
iii) Hygroscopic water is the only soil water available to roots of plant growing in soil as it is present inside the micropores.
iv) High temperature reduces use of water and solute absorption by roots.

a. i, ii, and iii only
b. ii, iii and iv
c. ii and iii only
d. i and ii only
Answer:
b. ii, iii and iv correct answer

Question 5.
Which of the given plant produces cardiac glycosides?
a. Calotropis
c. Nepenthes
b. Acacia
d. Utricularia
Answer:
a. Calotropis

Question 6.
Read the given statements and select the correct option.
i) Loamy soil is best suited for plant growth as it contains a mixture of silt, sand and clay.
ii) The process of humification is slow in case of organic remains containing a large amount of lignin and cellulose.
iii) Capillary water is the only water available to plant roots as it is present inside the micropores.
iv) Leaves of shade plant have more total chlorophyll per reaction centre, low ratio of chi a and chi b are usually thinner leaves.
a. i, ii and iii only
b. ii, iii and iv only
c. i, ii and iv only
d. ii and iii only
Answer:
d. ii and iii only

Question 7.
Read the given statements and select the correct option.
Statement A: Cattle do not graze on weeds of Calotropis.
Statement B : Calotropis have thorns and spines, as defense against herbivores.
a. Both statements A and B are incorrect.
b. Statement A is correct but statement B is incorrect.
c. Both statements A and B are correct but statement B is not the correct explanation of statement A.
d. Both statements A and B are correct and statement B is the correct explanation of statement A.
Answer:
b. Statement A is correct but statement

Question 8.
In soil water available for plants is
a. gravitational water
b. chemically bound water
c. capillary water
d. hygroscopic water
Answer:
c. capillary water

Question 9.
Read the following statements and fill up the blanks with correct option.
i) Total soil water content in soil is called ……………………………..
ii) Soil water not available to plants is called ……………………………
iii) Soil water available to plants is called ……………………..

Answer:
a) i – Holard, ii-Echard, iii-Chresard

Question 10.
Column I represent the size of the soil particles and Column II represents type of soil components. Which of the following is correct match for the Column I and Column II

Answer:
c) I (iii), II (ii), III (i), IV (iv)

Question 11.
The plant of this group are adapted to live partly in water and partly above substratum and free from water
a. Xerophytes
b. Mesophytes
c. Hydrophytes
d. Halophytes
Answer:
d. Halophytes

Question 12.
Identify the A, B, C and D in the given table

Answer:
a) A (+) B – Parasitism, C (-), D – Amensalism

Question 13.
Ophrys an orchid resembling the female of an insect so as to able to get pollinated is due to phenomenon of
a. Myrmecophily
b. Ecological equivalents
c. Mimicry
d. None of these
Answer:
c. Mimicry

Question 14.
A free living nitrogen fixing cyanobacterium which can also form symbiotic association with the water fern Azolla
a. Nostoc
b. Anabaena
c. chlorella
d. Rhizobium
Answer:
b. Anabaena

Question 15.
Pedogenesis refers to
a. Fossils
b. Water
c. Population
d. Soil
Answer:
d. Soil

Question 16.
Mycorrhiza promotes plant growth by
a. Serving as a plant growth regulators
b. Absorbing inorganic ions from soil
c. Helping the plant in utilizing atmospheric nitrogen
d. Protecting the plant from infection
Answer:
b. Absorbing inorganic ions from soil

Question 17.
Which of the following plant has a non-succulent xerophytic and thick leathery leaves with waxy coating
a. Bryophyllum
b. Ruscus
c. Nerium
d. Calotropis
Answer:
c. Nerium

Question 18.
In a fresh water environment like pond, rooted autotrophs are
a. Nymphaea and typha
b. ‘ CeratophyllumandUtricularia
c. Wolffia and pistia
d. Azolla and lemna
Answer:
a. Nymphaea and typha

Question 19.
Match the following and choose the correct combination from the options given below:

Answer:
d (I) iv, (II) iii, (III) ii, (IV) v, (V) i

Question 20.
Strong, sharp spines that get attached to animal’s feet are found in the fruits of
a. Ar gemone
b. Ecballium
c. Heritier
d. Crossandra
Answer:
a. Argemone

Question 21.
Sticky glands of Boerhaavia and Cleome support
a. Anemochory
b. Zoochory
c. Autochory
d. Hydrochory
Answer:
b. Zoochory

Question 22.
Define ecology.
Answer:
Ecology is the study of the reciprocal relationship between living organisms and their environment.

Question 23.
What is the ecological hierarchy? Name the levels of ecological hierarchy.
Answer:
Ecological hierarchy is the interaction of organisms with their environment results in the establishment of a grouping of organisms. Which is called ecological hierarchy (or) ecological levels of organisation.

Question 24.
What are ecological equivalents? Give one example.
Answer:
Taxonomically different species occupying similar habitats (Niches) in different geographical regions are called Ecological equivalents.
E.g: Certain species of epiphytic orchids of Western Ghats of India differ from the epiphytic orchids of South America. But they are epiphytes.

Question 25.
Distinguish habitat and niche
Answer:
Habitat

1. A specific phsical space occupied bv an organism (species)
2. The same habitat may be shared by many organisms (species)
3. Habitat specificity is exhibited by organisms.

Niche

1. A functional space occupied by an organism in the same ecosystem
2. A single niche is occupied by a single species
3. Organisms may change their niche with time and season.

Question 26.
Why are some organisms called eurythermal and some others stenohaline?
Answer:

1. Eurythermal: Organisms which can tolerate a wide range of temperature fluctuations.
   Example: Zostera.
2. Stenothermal: Organisms that can tolerate only a small range of temperature variations.
   Example: Mango.

Question 27.
‘Green algae are not likely to be found in the deepest strata of the ocean’. Give at least one reason.
Answer:

• The deepest strata of the ocean is dark and sufficient light is not available for the photosynthesis of green algae.
• Algae need brackish water for its growth. Which is also not available in the deepest strata of the ocean.

Question 28.
What is Phytoremediation?
Answer:
Phytoremediation refers to the using of living green plants to overcome soil or water contamination.
E.g: Growing Eichhomia in cadmium enriched soil reduces the level of cadmium.

Question 29.
What is the Albedo effect and write their effects?
Answer:

• The albedo effect is due to greenhouse effect.
• Aerosols (suspension of fine solid (or) liquid particles in gas) with small particles is reflecting the solar radiation entering the atmosphere is known as Albedo effect.
• It reduces the temperature, photosynthesis and respiration
• The sulphur compounds present in the aerosol are responsible for acid rain due to acidification of rain water and destroy the ozone.

Question 30.
The organic horizon is generally absent from agricultural soils because tilling, e.g., ploughing, buries organic matter. Why is an organic horizon generally absent in desert soils?
Answer:
Organic horizon is generally absent in deserts because of low content of organic matter due to scarcity of plant and animal remains or excreta.

Question 31.
Soil formation can be initiated by biological organisms. Explain how?
Answer:

• Soil formation is initiated by the weathering process.
• Biological weathering takes place when organisms like bacteria, fungi, lichens and plants helps in the breakdown of rocks through the production of acids and certain chemical substances.

Question 32.
Sandy soil is not suitable for cultivation. Explain why?
Answer:
Sandy soil has a high porosity leading to decreased water retention hence unfit for cultivation.

Question 33.
Describe the mutual relationship between the fig and wasp and comment on the phenomenon that operates in this relationship.
Answer:

• Mutualism interaction exist between fig tree and wasp
• In fig tree there is a tight one to one relationship with a pollinator species of wasp and no other species.
• The wasp pollinates the fig while finding egg lav ing sites and in turn, the fig offers the wasp developing seeds, as food for the developing larvae.

Question 34.
Lichen is considered as a good example of obligate mutualism. Explain.
Answer:

• It is an interaction between two species of organisms in which both are benefitted from the obligate association.
• Lichens is a mutual association of algae and a fungus.
• The alga is usually green alga (or) blue green alga. The fungus is an ascomycete (or) basidiomycete.
• It is believed that alga contributes organic food from photosynthesis and the fungus is able to absorb water and mineral salts.
• The fungus can also conserver water and this enables lichens to grow in extremely dry conditions where no other plants can exist.

Question 35.
What is mutualism? Mention any two examples where the organisms involved are commercially exploited in modern agriculture.
Answer:

• Mutualism is an interaction between two species of organisms in which both are benefitted from their association.
• Eg: 1 – Water Fern (Azolla) and Nitrogen fixing Cyanobacterium (Anabaena)
• Eg: 2 – Roots of terrestrial plants and fungal hyphae – Mycorrhiza.

Question 36.
List any two adaptive features evolved in parasites enabling them to live successfully on their host?
Answer:
Holoparasites:
The organisms which are dependent upon the host plants for their entire nutrition are called Holoparasites. They are also called total parasites.

Examples:

• Cuscuta is a total stem parasite of the host plant Acacia, Duranta, and manv other plants. Cuscuta even gets flower inducing hormone from its host plant.
• Balanophora, orobanche, and refflesia are the total root parasites found on higher plants.

Hemiparasites:
The organisms which derive only water and minerals from their host plant while synthesizing their own food by photosynthesis are called Hemiparasites. They are also called partial parasites.
Examples:
Viscum and Loranthus are partial stem parasites.

Question 37.
Mention any two significant roles predation plays in nature.
Answer:
Predation:

• It is an interaction between two species, one of which captures, kills, and eats up the other.
• The species which kills is called a predator and the species which is killed is called prey.
• The predator is benefitted while the prey is harmed.

Examples:
A number of plants like Drosera (Sundew Plant), Nepenthes (Pitcher Plant), Diaonaea (Venus flytrap), Utricularia (Bladderwort), and Sarracenia are predators

• which consume insects and other small animals for their food as a source of nitrogen.
• They are also called insectivorous plants.
• Many herbivores are predators. Cattles, Camels, Goats, etc., frequently browse on the tender shoots of herbs, shrubs, and trees.
• Generally, annuals suffer more than perennials.
• Grazing and browsing may cause remarkable changes in vegetation.
• Nearly 25 percent of all insects are known as phytophagous (feeds on plant sap and other parts of the plant)

Many defense mechanisms are envoloved to avoid their predations by plants.
Calotropis produces highly poisonous cardiac glycosides.
Tobacco: Produces nicotine.
Coffee: coffee plants produce coffeine.

Question 38.
How does an orchid ophrys ensure its pollination by bees?
Answer:
The plant, Ophrys an orchid, the flower looks like a female insect to attract the male insect to get pollinated by the male insect and it is otherwise called ‘floral mimicry.’

Question 39.
Water is very essential for life. Write any three features for plants which enable them to survive in water scarce environment.
Answer:

• Xerophytes are the plants which are living in dry (or) xeric condition are known as xerophytes.

Adaptations of xerophytes:

• Root system is well developed and is greater than that of shoot system.
• In some xerophytes all the internodes in the stem are modified into a fleshy leaf structure called phvlloclades (Opuntia)
• In some the petiole is modified into a fleshy leaf like structure called phyllode (Acacia melanoxylon).

Question 40.
Why do submerged plants receive weak illumination than exposed floating plants in a lake?
Answer:

• Submerged plants which receive weak illumination because
• Submerged plants are completely immersed in water and not in contact with the atmosphere (or) surface of the water.
• The floating hydrophytes float freely (or) float their leaves and flowers on the surface of water do not allow light to pass inside the lake.
• So submerged plants receive weak illumination than exposed floating plants.

Question 41.
What is vivipary? Name a plant group which exhibits vivipary.
Answer:

•  Vivipary is the special type of seed germination
• During germination, the seed is till attached to the parent plant and nourished by it.
• Vivipary generally occurs in mangrove plants.
• The mangrove plants are medium sized trees which grow in salty marshes of sea coasts. (Eg.) Rhizophora, Sonneratia, Avicennia.
• The seeds of this plant cannot germinate on the marshy habitat because of the excessive salt concentration and lack of oxygen.
• The radicle of the plant elongates considerably and projects out of the fruit.
• Then dark like seedling breaks off from the parent plant.
• Then radicle immediately forms new roots and establishes the seedling as a new plant.

Question 42.
What is thermal stratification? Mention their types.
Answer:
Thermal Stratification is usually found in aquatic habitats. The change in the temperature profile with increasing depth in a water body is called thermal stratification. There are three kinds of thermal stratifications.

1. Epilimnion – The upper layer of warmer water.
2. Metalimnion – The middle layer with a zone of a gradual decrease in temperature.
3. Hypolimnion – The bottom layer of colder water.

Question 43.
How is rhytidome act as the structural defence by plants against fire?
Answer:

• Rhytidome is the structural defense by plants against fire
• The outer bark of trees which extends to the last formed periderm is called Rhytidome.
• It is composed of multiple layers of suberized periderm, cortical and phloem tissues.
• It protects the stem against fire, water loss, invasion of insects and prevents infections by microorganisms.

Question 44.
What is myrmecophily?
Answer:
Sometimes, ants take their shelter on some trees such as Mango, Litchi, Jamun, and Acacia, etc. These ants act as bodyguards of the plants against any disturbing agent and the plants, in turn, provide food and shelter to these ants. This phenomenon is known as Myrmecophily. Example: Acacia and its ants.

Question 45.
What is a seed ball?
Answer:

• It is a method of human aided seed dispersal r Seed ball is an ancient Japanese technique of encasing
• seeds in a mixture of clay and soil humus (also in cow dung) and scattering them on suitable ground, not planting of trees manually.
• This method is suitable for barren and degraded lands for tree regeneration and vegetation before the monsoon period where the suitable dispersal agents become rare.

Question 46.
How is anemochory differ from zoochory?
Answer:

Question 47.
What is co evolution?
Answer:
The interaction between organisms, when continues for generations, involves reciprocal changes in genetic and morphological characters of both organisms. This type of evolution is called Co-evolution. It is a kind of co-adaptation and mutual change among interactive species.
Examples:

• Corolla length and probosci’s length of butterflies and moths (Habenaria and Moth).
• Bird’s beak shape and flower shape and size.

Question 48.
Explain Raunkiaer classification of the world’s vegetation based on temperature.
Answer:
Based on the temperature prevailing in an area, Raunkiaer classified the world’s vegetation into the following four types.

They are megatherms, mesotherms, microtherms, and hekistotherms.
In thermal springs and deep sea hydrothermal vents where average temperature exceed 100°c.

Based on the range of thermal tolerance, organisms are divided into two types.

• Eurythermal: Organisms which can tolerate a wide range of temperature fluctuations.
  (Eg.) Zostera (A marine Angiosperm) and Artemisia tridentata.
• Stenothermal: Organisms which can tolerate only a small range of temperature variations.
  (Eg.) Mango and Palm (Terrestrial Angiosperms).

Mango plants do not and cannot grow in temperate countries like Canada and Germany.

Thermal stratifications:
It is usually found in aquatic habitat.
The change in the temperature profile with increasing depth in a water body is called thermal stratification. There are three kinds of thermal stratification

1. Epilimniotn The upper layer of warmer water
2. Metalimnion The middle layer with a zone of gradual decrease in temperature.
3. Hypolimnion The bottom layer of colder water.

Temperature based zonation:
Variations are latitude and altitude do affect the temperature of the vegetation on the earth’s surface.
Latitude: Latitude is an angle which ranges from 0° at the equator to 90° at the poles.
Altitude: How High a place is located above the sea level is called the altitude of the place.

Question 49.
List out the effects of fire on plants.
Answer:
Effects of fire:

• A fire has a direct lethal effect on plants
• Burning scars are suitable places for the entry of parasitic fungi and insects
• It brings out the alteration of light, rainfall, nutrient cycle, the fertility of the soil, pH, soil flora, and fauna
• Some fungi which grow in the soil of burnt areas called pyrophilous. (Eg.) Pyronema confluens.

Question 50.
What is the soil profile? Explain the characters of different soil horizons.
Answer:
Soil Profile:

• Soil is commonly stratified into horizons at different depth. These layers differ in their physical, chemical and biological properties.
• This succession of super-imposed horizons is called a soil profile.

Question 51.
Give an account of various types of parasitism with examples.
Answer:
(a) Parasitism: It is an interaction between two different species in which the smaller partner (parasite) obtains food from the larger partner (host or plant). So the parasitic species is benefitted while the host species is harmed. Based on the host-parasite relationship, parasitism is classified into two types they are holoparasite and hemiparasite.

(b) Holoparasites: The organisms which are dependent upon the host plants for their entire nutrition are called Holoparasites. They are also called total parasites.
Examples:

• Cuscuta is a total stem parasite of the host plant Acacia, Duranta and many other plants. Cuscuta even gets flower inducing hormone from its host plant.
• Balanophora, Orobanche and Rafflesia are the total root parasites found on higher plants.

(c) Hemiparasites: The organisms which derive only water and minerals from their host plant while synthesizing their own food by photosynthesis are called Hemiparasites. They are also called partial parasites.
Examples:

• Viscum and Loranthus are partial stem parasites.
• Santalum (Sandal Wood) is a partial root parasite.
  The parasitic plants produce the haustorial roots inside the host plant to absorb nutrients from the vascular tissues of host plants.

Question 52.
Explain different types of hydrophytes with examples.
Answer:
The plants which are living in water or wet places are called hydrophytes. According to their relation to water and air, they are sub-divided into the following categories:

• Free floating hydrophytes: These plants float freely on the surface of the water. They remain in contact with water and air, but not with soil. Examples: Eichhornia, Pistia and Wolffia (smallest flowering plant).
• Rooted floating hydrophytes : In these plants, the roots are fixed in mud, but their leaves and flowers are floating on the surface of water. These plants are in contact with soil, water and air. Examples: Nelumbo, Nymphaea, Potomogeton, and Marsilea.
• Submerged floating hydrophytes: These plants are completely submerged in water and not in contact with soil and air. Examples: Ceratophyllum and Utricularia.
• Rooted- submerged hydrophytes : These plants are completely submerged in water and rooted in soil and not in contact with air. Examples: Hydrilla, Vallisneria, and Isoetes.

Amphibious hydrophytes (Rooted emergent hydrophytes): These plants are adapted to both aquatic and terrestrial modes of life. They grow in shallow water. Examples: Ranunculus, Typha and Sagittaria.
Hygrophytes: The plants which can grow in moist damp and shady places are called hygrophytes. (Eg.) Habenaria (Orchid), Mosses (Bryophytes), etc.

Question 53.
Enumerate the anatomical adaptations of xerophytes.
Answer:
Anatomical adaptations:

• Presence of multilayered epidermis with heavy cuticle to prevent water loss due to transpiration.
• The hypodermis is well developed with sclerenchymatous tissues.
• Sunken shaped stomata are present only in the lower epidermis with hairs in the sunken pits.
• Scotoactive type of stomata found in succulent plants.
• Vascular bundles are well developed with several layered bundle sheath.
• Mesophyll is well differentiated into palisade and spongy parenchyma.
• In succulents the stem possesses a water storage region.

Question 54.
List out any five morphological adaptations of halophytes.
Answer:
Morphological adaptations:

• The temperate halophytes are herbaceous but the tropical halophytes are mostly bushy
• In addition to the normal roots, many stilt roots are developed
• A special type of negatively geotropic roots called pneumatophores with pneumathodes to get sufficient aeration are also present. They are called breathing roots.
  Example: Avicennia

• Presence of thick cuticle on the aerial parts of the plant body
• Leaves are thick, entire, succulent and glossy. Some species are aphyllous (without leaves).
• Vivipary mode of seed germination is found in halophytes

Question 55.
What are the advantages of seed dispersal?
Answer:
Advantages of seed dispersal:

1. Seeds escape from mortality near the parent plants due to predation by animals or getting diseases and also avoiding competition.
2. Dispersal also gives a chance to occupy favourable sites for growth.
3. It is an important process in the movement of plant genes, particularly this is the only method available for self-fertilized flowers and maternally transmitted genes in outcrossing plants.
4. Seed dispersal by animals helps in conservation of many species even in human-altered ecosystems.
5. Understanding of fruits and seed dispersal acts as a key for proper functioning and establishment of many ecosystems from deserts to evergreen forests and also for the maintenance of biodiversity conservation and restoration of ecosystems.

Question 56.
Describe dispersal of fruit and seeds by animals.
Answer:
Birds and mammals, including human beings, play an efficient and important role in the dispersal of fruit and seeds. They have the following devices,

i. Hooked fruit: The surface of the fruit or seeds have hooks,(Xanthium), barbs (Andropogon), spines (Aristida) by means of which they adhere to the body of animals or clothes of human beings and get dispersed.

ii. Sticky fruits and seeds:

• Some fruits have sticky glandular hairs by which they adhere to the fur of grazing animals. Example: Boerhaavia and Cleome.
• Some fruits have a viscid layer which adheres to the beak of the bird which eats them and when they rub them on to the branch of the tree, they disperse and germinate. Example: Cordia and Alangium

iii. Fleshy fruits: Some fleshy fruits with conspicuous colours are dispersed by human beings to distant places after consumption. Example: Mango and Diplocyclos

12th Bio Botany Guide Principles of Ecology Additional Important Questions and Answers

I. Match the following

Question 1.

a. A – (4), B – (1), C – (3), D – (2)
b. A – (3), B – (1), C – (2), D – (4)
c. A – (2), B – (1), C – (4), D – (3)
d. A – (2), B – (4), C – (1), D – (3)
Answer:
d. A – (2), B – (4), C – (1), D – (3)

Question 2.

a. A – (4), B – (3), C – (2), D – (1)
b. A – (3), B – (1), C – (4), D – (2)
c. A – (1), B – (2), C – (3), D – (4)
d. A – (2), B – (3), C – (4), D – (1)
Answer:
b. A – (3), B – (1), C – (4), D – (2)

Question 3.

a. A – (1), B – (2), C – (3), D – (4)
b. A – (2), B – (3), C – (1), D – (4)
c. A – (3), B – (4), C – (1), D – (2)
d. A – (2), B – (3), C – (1), D – (4):
Answer:
c. A – (3), B – (4), C – (1), D – (2)

Question 4.

a. -(1), B – (2), C – (3), D – (4)
b. A -(2), B – (3), C – (1), D – (4)
c. A – (4), B – (3), C – (2), D – (1)
d. A – (3), B – (4), C – (1), D – (2)
Answer:
d. A – (3), B – (4), C – (1), D – (2)

Question 5.

. A – (ii), B – (iv), C – (i), D – (iii) b. A – (ii), B – (iii), C – (iv), D – (i)
c. A – (iii), B – (iv), C – (i), D – (ii) d. A – (iv), B – (iii), C – (ii), D – (i)

Question 6.

Anwer:
a. A – (ii), B – (iv), C – (i), D – (iii)

Question 7.

a. A- (i), B- (iii), C- (ii), D- (iv)
b. A- (i), B- (ii),C- (iii), D- (iv)
c. A- (iv), B- (iii), C- (ii), D (i)
d. A- (ii), B- (iii), C- (i), D- (iv)
Answer:
b. A- (iii),B- (ii),C- (iv),D- (i)

Question 8.
Match the following
Read the statement and fill it with correct (A) and (B)
In Halophytes …………….. shape sclereids and …………………. heavily thickened spicules that provide mechanical strength to the cortex are present in the stem.

Answer:
c) A – Star- B – H-shape

9. Match the following
Read the statement and fill it with correct (A), (B) and (C)
It is the structural defence by plants against fire. The outer bark of trees which extends to the last formed ………… A……………. is called Rhytidome. It is composed of multiple layers of suberised …………..B……………… cortical and ……….C………….. tissues.

Answer:
c) A-Periderm, B – Periderm, C – Phloem

II. Pick out the correct pair.

A) Oxylophytes – Plants living ice surface
B) Hollard – Total soil water content
C) Chresard – Water not available to plants
D) Echard – Water available to plants
Answer:
B) Hollard – Total soil water content

III. Choose the incorrect statements and select the option.

Question 1.
A) Some fungi which grow in soil of burnt areas called pyrophilous
B) Pyronema confluens is the indicator of fire.
C) Lagoons salinity will be more than 100%
D) Low temperature with high humidity helps the plants to become disease-free
a. None of these
b. A alone
c. A, B and C
d. D alone
Answer:
d. D alone

Question 2.
A) Applied ecology help us to manage and conserve the natural resource.
B) Niche – The term was coined by the naturalist Roswell Hill Johnson.
C) Halophytes are the plants which lives in saltwater.
D) Metalimnion is a zone of a gradual decrease in temperature.
a. A and B
b. A, B, and C
c. C and D
d. C alone
Answer:
d. C alone

Question 3.
Choose the incorrect one with respect to type of soil particles.

Answer:

Question 4.
A) R – Horizon consists of parent bedrock.
B) C – Horizon is partially weathered horizon.
C) B – Horizon is rich in minerals.
D) A – Horizon is often rich in humus and minerals.
a. A, B and C
b. B, C, D
c. None of these
d. C, A, and B
Answer:
c. None of these

Question 5.
a. Hollard is total soil water content
b. Echard is water not available to plant
c. The visible part of the light is made up of wavelengths from 400 nm to 700 nm
d. July 06 is Van Mahostav day
Answer:
d. July 06 is Van Mahostav day

VI. Choose the incorrect pair

Question 1.

a. A – 3), B – 4), C – 2), D – 1)
c. A – 2), B – 3), C – 4), D – 1)
b. A – 4), B – 2), C – 3), D – 1)
d. A – 1), B – 2), C – 3), D – 4)
Answer:
a. A – 3), B – 4), C – 2), D – 1)

Question 2.
Choose the incorrect pair which is related to mimicry.
A) Ophrys an orchid is an example of floral mimicry.
B) Carausius morosus – Stick insect is an example of protective mimicry.
C) Phyllium frondosum – Leaf insect another example of protective mimicry.
D) Ants take their shelter on Mango, Litchi
a. A, Band C b. B, C and D c. C alone d. None of these
Answer:
d. None of these

V. Assertion and Reason

Question 1.
Assertion(A): Hypolimniotic layer of water is always cold.
Reason (R): The water holds the temperature of the soil at the bottom of pond
a. (A) correct; (R) wrong
b. Both (A) and (R) are correct, but (R) is not the correct explanation of (A)
c. Both (A) and (R) are correct; (R) is the correct explanation of (A)
d. Both (A) and (R) are wrong.
Answer:
a. (A) correct; (R) wrong

Question 2.
Assertion: Non-succulent plants are called drought resistant plants.
Reason: They have many adaptation to resist dry conditions.
a. A is correct R is wrong
b. A is the wrong R is correct
c. Both are wrong
d. A is correct R is the correct explanation of A
Answer:
d. A is correct R is the correct explanation of A

VI. odd man out

Question 1.
Choose the odd man out:
Hornbills,
Slitz size of pollina of Apocynaceae,
Birds of scrub jungles,
Leg size of insect camel’s foot climber
Answer:
Leg size of insect camel’s foot climber

Question 2.
Choose the odd man out:
Isoetes
Hydrilla,
Potamogeton
Ranunculus Mukia.
Answer:
Ranunculus Mukia

Question 3.
Choose the odd man out:
Argemone,
Mollugo,
Tribulus
Bryophyllum
Answer:
Bryophyllum

VII. Pictorial Questions

Question 1.
Observe the diagram and choose their part from the following option.

a. Petiole, phyllode
b. Stem, leaf
c. Spines, leaves
d. Stem, Scale leaves
Answer:
d. Stem, Scale leaves

Question 2.
Observe the diagram and write the name of this plant.

Answer:
Ceratophyllum

Question 3.
Observe the diagram and choose the correct vegetation option for A, B, C and D

a. Tundra, ice, treeline, desert
b. Rain, coniferous, tropical, grass land
c. Grass, conifer, tropical, deciduous
d. Coniferous, deciduous, grassland
Answer:
d. Coniferous, deciduous, grassland

Question 4.
Draw the diagram showing altitudinal zonation of vegetation.

VIII. True or False

Question 1.
Read the sentences and select the correct options stating which ones are true (T) and which ones are false (F).
A) Juglone which inhibits the growth of seedlings of Apple, Tomato and Alfalfa around it.
B) Penicillin which inhibits the growth of staphylococcus bacteria.
C) Amensalism is not antibiosis.
D) Trichoderma inhibit the growth of Aspergillus.

Answer:
C) T, T, F, T

IX. Fill in the blanks Answers

1. Roots and hulls of Black Walnut Juglans nigra secretes an alkaloid……………………………………….
Answer:
Juglone

2. The plants which behave as xerophytes at summer and behave as mesophvtes during rainv season is……………………………….
Answer:
tropophytes

3. The ……………………………….wave length of spectrum is less strongly absorbed by plants.
Answer:
green (500 – 600 nm)

4. The rate of photosynthesis is maximum at blue (400 – 500 nm) and……………………………….
Answer:
red (600 – 700 nm)

5. ……………………………….is well known factor needed for the physiological process of plants.
Answer:
Light

6. In climatology diurnal cycle is the basic form of climatic pattern in every ………………………………..
Answer:
24 hrs.

7. The altitudinal limit of normal tree growth is about ………………………………..
Answer:
3000 to 4000

8. ……………………………….are organisms, which derive onlv water and minerals from their host plant for synthesizing their own food.
Answer:
Hemiparasites

9. ……………………………….is the smallest free floating hvdrophvtes.
Answer:
Wolffia

10. Scotoactive tvpe of stomata found in ……………………………….plants.
Answer:
succulent

11. ……………………………….are plants which grow perched on other plants.
Answer:
Epiphytes

12. The plants which are living in moderate conditions (neither too wet nor too drv) are known as……………………………….
Answer:
Mesophytes

13. ……………………………….is the world forest dav.
Answer:
March – 21

14. Earth dav falls on……………………………….
Answer:
April – 22

15. International ozone dav is celebrated on……………………………….
Answer:
September -16

X. Choose the correct answer

Question 1.
Which one of the following is not related to mutualism.
a. Anabaena present in coralloid root of cycas.
b. Wasps present in fruits of fig.
c. Tillandsia grows on the bark of oak and pine trees.
d. Cyanobacterium (Nostoc) found in the thalloid body of Anthoceros.
Answer:
c. Tillandsia grows on the bark of oak and pine trees.

Question 2.
Dionaea, Bladder wort and sarracenia are
a. Epiphytes
b. Commensals
c. Predators
d. Parasites
Answer:
c. Predators

Question 3.
Tobacco produces nicotine, coffee plants produce caffeine, cinchona plant produce quinine it is meant for…………….
a. Predators
b. Defence mechanism
c. Proto cooperation
d. Holoparasites
Answer:
b. Defence mechanism

Question 4.
Which of the following is not related to parasitism.
a. Acacia, Duranta – cuscuta
b. Balanophora,Orabanche and Refflesia – higher plants.
c. Pitcher plant with insect
d. Viscum and Loranthus – Stem parasite
Answer:
c. Pitcher plant with insect

Question 5.
Which plant pods explodes with a loud noise like cracker?
a. Boerhaavia
b.Cleome
c. Bauhinia vahlii
d.Ecballium elatrium
Answer:
d. Ecballium elatrium

Question 6.
Casuarina, Nerium, Ziziphus and Acacia examples for
a.Truexerophytes
b. Succulents
c. Ephemerals
d. Phyllode
Answer:
a. True xerophytes

Question 7.
Root pockets are present in
a. Eichhornia
b. Nelumbo
c. Potamogeton
d. Ceratophyllum
Answer:
a. Eichhornia

Question 8.
Stenophagic means
a. The organism can survive by taking wide range of food.
b. The organism can survive by taking narrow range of food.
c. The organism can live in water with wide range of salinity
d. The organism can live in water with narrow range of salinity.
Answer:
a. The organism can survive by taking wide range of food.

Question 9.
In euphorbia, acacia, ziziphus and capparis are modified into spines.
a. Stipules
b. Scales
c. Leaves
d. Bud
Answer:
a. Stipules

Question 10.
Latitude, altitude, direction of mountain, steepness of mountain etc are factors.
a. Topographic
b. Ecotone
c. Altitude
d. Edge effect
Answer:
a. Topographic

Question 11.
The roots of orchids which contain special type of spongy tissue called
a. Xylem
b. Phloem
c. Parenchyma
d. V elamen
Answer:
d. Velamen

Question 12.
Thorns of Bougainvillea, spines of opuntia and latex of cacti protect them from
a. Drought
b. Parasites
c. Predators
d. Insects
Answer:
c. Predators

Question 13.
Which seeds showing highest longevity in plant kingdom.
a. Lotus
b. Hydrilla
c. Nymphaea
d. Marsilea
Answer:
a. Lotus

Question 14.
plants are completing life cycle within a short period.
a. Lotus
b. Hydrilla
c. Nymphaea
d. Marsilea
Answer:
a. Lotus

XI. Two Marks

Question 1.
What is biotope and ecotope?
Answer:
The environment of any community is called biotope.
The habitat and niche of any organism is called ecotope.

Question 2.
What is biome?
Answer:
Biome is a large naturally occurring community of flora and fauna occupying in a major habitat. (Eg.) forest, fundra

Question 3.
Difference between evergreen forest and sclerophyllous forest?
Answer:
Evergreen forest
It is found where heavy rainfall occurs throughout the year.

Sclerophyllous forest
It is found where heavy rainfall occurs during winter and low rainfall during summer.

Give reason for the following

• Species of the grass lands of western ghats of India differ from the grass species of temperate grass lands of steppe in North America. But they are all ecologically primary producers.
• Taxonomically different species occupying similar habitats (Niche) in different geographical regions are called ecological equivalents.

Question 4.
What are the various latitudinal zonation of vegetation ?
Answer:
Tropical rain forest, grassland (or) desert, deciduous forest, coniferous forest, treeline (or) tundra, snow (or) ice.

Question 5.
What are the various altitudinal zonation of vegetation?
Answer:
Tropical rain forest, grassland (or) desert, deciduous forest, coniferous forest, tundra snow are the various vegetation of altitudinal zonation.

Question 6.
Differentiate between euryhaline and stenohaline.
Answer:
Euryhaline Stenohaline

1. Organisms which can live in water with wide range of salinity.
2. (Eg.) Marine algae and marine angiosperms

stenohaline.

1. Organisms which can withstand only small range of salinity.
2. (Eg.) Plants of estuaries

Question 7.
What is albedo effect ?
Answer:

• Aerosols with small particles is reflecting the solar radiation entering the atmosphere called albedo effect.
• It reduces the temperature limits, photo synthesis and respiration.

Question 8.
Define : Indicators of fire (or) Why pteris and pyronema are called as fire indicators?
Answer:

• Some pteris are well adapted to grow in burnt and highly disturbed area
• Pteris (fern) and pyronema (fungus) indicates the burnt up and fire disturbed areas.
• So they are called indicators of fire.

Question 9.
What is edge effect?
Answer:

• Some species are found in the ecotone areas border between forest and grassland due to the effect of the environment of the two habitats. This is called the edge effect.
• (Eg.) Owl in the ecotone area between forest and grassland.

Question 10.
What is the ecotone area?
Answer:
The transition zone between two ecosystems. (Eg.) The border between forest and grassland.

Question 11.
Why do valleys are rich in vegetation compare to the steepness of the mountain?
Answer:

• The steepness of the mountain (or) hill allows the rain to run off.
• Asa result the loss of water causes water deficit and quick erosion of the top soil resulting in poor vegetation.
• On the other hand the plains and valley are rich in vegetation due to the slow drain of surface water and retention of water in the soil.

Question 12.
Draw the picture and mark the A and B.
Write the name of the plant which is present on the host trunk.
Answer:

Question 13.
Write the examples for the following type of holo parasites (or) total parasites.
a) Total stem parasite:………………
b) Total root parasite on higher plants :……………., …………………, ……………..
Answer:
a) Cuscuta
b) Balanophora, Orobanche and Reflesia.

Question 14.
Write the examples for the following type of hemi parasites (or) partial parasites.
a) Partial stem parasite :……………… , ………………
b) Partial root parasite:………………
Answer:
a) Viscum and Loranthus
b) Santalum (sandal wood)

Question 15.
“The utricularia (Bladderwort) competes with tiny fishes for small crustaceans and insects” What type of interaction exist in the above examples.
Answer:

• Inter-specific competition is exist in the above examples.
• It is an interaction between individuals of different species for common need.

Question 16.
What is intra specific competition ?
Answer:

• It is an interaction between individuals same species.
• It is very severe because all the members of species have similar requirement of food habitat, pollination etc.

Question 17.
What is the competition?
Answer:
It is an interaction between two organisms (or) species in which both the organisms (or) species are harmed.

Question 18.
What is junglone?
Answer:
Roots and hulls of black walnut junglone nigra secretes an alkaloid junglone.

• Which inhibits the growth of seedlings of apple,tomato and alfalfa around it.
• It is an example for amensalism type of interspecific interaction.

Question 19.
What are trichophyllous plants? Give example.
Answer:
In xerophytes, the leaves and stem are covered with hairs are called trichophyllous plants. (Eg.) cucurbits, (melothria and mukia)

Question 20.
Orchids, money plant and lianas are epiphytes. Why? (or) What are epiphytes give an example.
Answer:

• Many orchids ferns, lianas, money plant usnea (lichen) are some of examples of epiphytes.
• These plants which are found on other plants and growing without harming them are called epiphytes.

Question 21.
What are tropophytes?
Answer:
Tropophytes are plants which behave as xerophytes at summer and behave as mesophytes (or) hydrophytes during rainy season.

Question 22.
Seeds of maple gyrocarpus, dipterocarpus and terminalia exhibit which type of adaptations for dispersal of fruits and seeds?
Answer:
Seeds (or) whole fruits are flattened to form a wing for dispersal by wind.

Question 23.
Guess !! Who am I………….? I am dispersed by ant and I have caruncle.
Answer:

• Caruncle is a structure found in micropylar region of euphorbiaceae seeds, that attract ants. Which feed the caruncle to their larvae.
• Then ants leave the seed to their waste disposal area. Where the seeds germinate.
• This type of seed dispersal called myrmecophily.

Question 24.
What are xerophytes ? What are its types ?
Answer:
Xerophytes are plants, which are living in dry (or) xeric conditions are known as xerophytes. They are a) Physical dryness, b) Physiological dryness

Question 25.
In some habitats, water is sufficiently present but plants are unable to absorb it. Why? How do you call it?
Answer:

• It is called physiological dryness.
• In these habitats, water is sufficiently present but plants are unable to absorb it because of the absence of capillary spaces.
• (Eg.) Plants in salty and acidic soil.

Question 26.
Define pedology
Answer:
The study of soils is called pedology

Question 27.
What is palaeoclimatology? Give an example.
Answer:

• Helps to reconstruct past climates of our planet and flora, fauna and ecosystem in which they lived.
• Example : Air bubbles trapped in ice for tens of thousands of years with fossilized pollen, coral, plant and animal debris.

Question 28.
What is sclerophyllous forests?
Answer:
Found where heavy rainfall occurs during winter and low rainfall during summer.

Question 29.
Define Anemometer?
Answer:

• Air in motion is called wind.
• It is also a vital ecdogical factor.
• The atmospheric air contains a number of gases, particles and other constituents.
• Anemometer is the instrument used to measure the speed of wind.

Question 30.
Which is Nitrogen fixation?
Answer:
Rhizoblum (Bacterium) forms nodules in the roots of leguminous plants and lives symbiotically.
The Rhizobium obrains food from leguminous plant and in turn fixes atmospheric nitrogen in to nitrate, making it available to host plants.

XII. Three Marks

Question 1.
Is there any limit of tree growth related to altitude ? (or) What is treeline or timberline?
Answer:

• Timberline (or) tree line is an imaginary line in a mountain (or) higher areas of land that marks the level above which trees do not
  grow.
• The altitudinal limit of normal tree growth is about 3000 to 4000 m.

Question 2.
How does Rhytidome protect the plant against forest fire?
Answer:

• It is the structural defense by plant against.
• The outer bark of trees which extends to the last formed periderm is called Rhytidome.
• It is composed of multiple layers of suberized periderm cortical and phloem tissue. It protects the stem against fire, water loss, invasion of insects and prevents infections by microorganism

Question 3.
Which branch of ecology help us to manage and conserve natural resources, particularly ecosystem? (or) What is applied ecology (or) environmental technology?
Answer:
Applied ecology (or) environmental technology helps us to manage and conserve natural resource particularly ecosystems, forest and wild life conservative management.

Environmental management involves bio-diversity, conservation, ecosystem restoration, habitat management, invasive SPS management protected areas management and also help us plan landscapes and environmental impact designing for the futuristic ecology.

Question 4.
What are ecological factors (or) environmental factors?
Answer:

• Many organisms co-exist in an environment.
• The environment includes physical, chemical biological component.
• When a component surrounding an organism affects the life of an organism called factor.
• These factors may be biotic and abiotic.

Question 5.
What are the environmental factors affecting a plant life?
Answer:

• Climatic factors : Sunlight, precipitation wind, carbon dioxide and water vapour.
• Biotic factors : Birds, insects, man, grazing animals, rodents, plant pathogens and epiphytes.
• Edaphic factors : Soil slope, soil water, physical nature of soil, minerals, soil air.

Question 6.
What are the various effects of light upon a green plant ?
Answer:
Various effects of light on green plants are photosynthesis, opening and closing of sto¬mata movements, germination of seeds, flowering tuber formation, runner production stem and leaf formation.

Question 7.
What is phytoremediation ? Given Example.
Answer:
Some plants are used to remove cadmium from contaminated soil is known as phyto remediation. tM.-fTiVM
(Eg.) Rice and eichhornia tolerate cadmium by binding it to their proteins.
Soybean and tomato manage to tolerate cadmium by storing into few group of cells.

Question 8.
Which soil is ideal for cultivation ? (or) Why loamy soil is ideal for cultivation ?
Answer:

• Loamy soil is ideal for cultivation. It consist of 70% sand and 30% clay (or) silt.
• It ensures good retention and proper drainage of water.
• The porosity of soil provides adequate aeration and allows the penetration of roots.

Question 9.
What is soil profile (or) super-imposed horizons?
Answer:

• Soil is commonly stratified into horizons at different depth.
• These layers differ in their physical, chemical and biological properties.
• This succession of super-imposed horizons is called soil profile.

Question 9.
Differentiate species ecology from community ecology.
Answer:
Species Ecology :
It is the study of a group of individual of particular species, (population)

Community Ecology :
It is the study of several species that are living together as a community (made up of several populations)

Question 10.
Why do vegetation at different altitude are varies ?
Answer:
Height above the sea level forms the altitude.
At high altitudes

• The velocity of wind remains high.
• Temperature and air pressure-decreases.
• While humidity and intensity of light increases.

Due to these factors vegetation at different altitudes varies showing distinct zonation.

Question 11.
Why do different types of vegetation occur from equator to poles (or) latitudes?
Answer:

• Latitudes represent distance from the equator.
• Temperature values are maximum at the equator and decrease gradually towards poles.
• So different types of vegetation occur in latitude.

Question 12.
What is topography? WTiat are its factors?
Answer:

• The surface features of earth are called topography.
• Its factors include, latitude, altitude, direction of mountain, steepness of mountain.

Question 13.
Spanish Moss-Tillandsia grows on the bark of oak and pine trees. Which type of interactions exist in the above examples ?
Answer:

• They were epiphytes showing commensalism type of positive interaction.
• In which one is benefitted and other is neither benefitted nor harmed.
• The species that derives benefit is called the commensal, while the other species is called the host.

Question 14.
What is velamen?
Answer:

• The epiphytic higher plant gets its nutrients and water from the atmosphere with the help of their hygroscopic roots.
• These roots contain special type of spongy tissue called velamen.

Question 15.
What is proto cooperation?
Answer:
An interaction between organisms of different species in which both organisms benefit but neither is dependent on the relationship.
(Eg.) Soil bacteria, fungi and plants growing in the soil.

Question 16.
Draw the picture and mark A, B and C

Answer:
A – Tendril, B – Pitcher, C – Lamina

Question 17.
Draw the diagram mark A, B and C.
Answer:
A – Haustoria, B – Host, C – Parasite

a) Name the parasite with example.
Answer:
Holoparasite Cuscuta.

Question 18.
What are holo parasites ? (or) total parasites.
Answer:
The organisms which are dependent upon the host plants for their entire nutrition are called holo parasites (or) total parasites. (Eg.) Cuscuta.

Question 19.
Trichoderma (fungus) inhibits the growth of fungus aspergillus. Why ? (or) What is amensalism? (or) WTiat is antibiosis?
Answer:

• It is an inter specific interaction in which one species is inhibited while the other species is neither benefitted nor harmed.
• The inhibition is achieved by secretion of chemicals called allelopathic substances.

Question 20.
Phyllium frondosum, carausius morosus exhibit what type of interactions ? (or) WTiat is mimicry?
Answer:

• It exhibits mimicry of inter specific interactions (or) mimicry of co-evolutionary dynamics.
• Mimicry is a phenomenon in which living organism modifies its form appearance structure (or) behaviour and looks like another living organism as a self defence and increases the chance of their survival.

Question 21.
What is kairomones ? (or) Which type of defence induced by the predator to the progeny of wild radish?
Answer:
kairomone is a chemical substance emitted by pieris rapae caterpillar (butterfly) exposed to wild radish gets the capacity to transmit defence induced by predator (butterfly) to progeny of wild radish.

Question 22.
Name the phenomenon which is exhibited by acacia and acacia ants ? What does it says?
Answer:

• Sometimes, ants take their shelter on some trees such as Mango, Litchi, Jamun, Acacia etc.
• These ants act as body guards of the plants against any disturbing agent and the plants in turn provide food and shelter to these ants.
• This phenomenon is known as Myrmecophily. Example: Acacia and acacia ants.

Question 23.
What is hygrophytes ? Why do they call so ?
Answer:
The plants which can grow in moist damp and shady places are called hygrophytes.
(Eg.) Habenaria (orchid),
Mosses (Bryophytes)

Question 24.
How do mangroves work to protect us from natural disaster with example.
Answer:

• Mangroves protect vulnerable coastal areas from wave action by holding the soil together and prevent coastal erosion.
• Out of three districts of Tamil Nadu (Nagapattinam, Thanjavur and Thiruvarur), Muthupet (Thiruvarur district) was less damaged by Gaja Cyclone (Nov-2018) due to the presence of mangrove forest.

Question 25.
Some plants are called drought evaders. Why?
Answer:

• Ephemerals are called drought evaders (or) drought escapers because
• These plants complete their life cycle within a short period, (single season)
• (Eg.) Argemone, Mollugo, Tribulus, Tephrosia.

Question 26.
What is the source of energy in deep sea?
Answer:

• In deep sea (>500 m) the environment is dark and its inhabitants are not aware of the existence of celestial source of energy called sun.
• Dead sea organisms use chemical energy rather than energy from sunlight.
• Chemosynthesis is a process, special bacteria use this process to produce energy without using sunlight.

Question 27.
Write any four ecologically important days.
Answer:

• March 21 – World Forest Day
• May 22 – World Biodiversity Day
• June 05 – World Environment Day
• July 07 – Van Mohot Stav day.

Question 28.
What is phylloclades (or) fleshy leaf? Give an example
Answer:
In some xerophytes all the internode in the stem are modified in to a fleshy leaf structure is called phylloclades.
Ex.→ opuntia

Question 29.
What is breathing roots? Give an example.
Answer:
A special type of negatively geotropic roots called pneumatophores with pneumathodes to get sufficient aeration are also present.
They are called breathing roots.
Example : Avicennia

Question 30.
Define cladode? Give an example
Answer:
In some of the others single or occasionally two internodes modified into fleshy green structure called cladode Example: Asparagus

Question 31.
Define phyllode?
Answer:
In some the petiole is modified into a fleshy leaf like structure called phyllode (Acacia melonoxylon)

XIII. Five Marks

Question 1.
What are the various zonation based on climatic factor temperature and its effects ?
Answer:
Temperature based zonation:

• Variations in latitude and altitude do affect the temperature and the vegetation on the earth surface.
• Timber line / Tree line : It is an imaginary line in a mountain or higher areas of land that marks the level above which trees do not grow. The altitudinal limit of normal tree growth is about 3000 to 4000m.

Effects of temperature:

• The following physiological processes are influenced by temperature:
• Temperature affects the enzymatic action of all the bio-chemical reactions in a plant body.
• It influences CO2 and O2 solubility in the biological systems. Increases respiration and stimulates growth of seedlings.
• Low temperature with high humidity can spread diseases to plants
• The varying temperature with moisture determines the distribution of the vegetation types.

Question 2.
What are the important climatic effects of wind on plants ?
Answer:
Effects of wind:

• Wind is an important factor for the formation of rain
• Causes wave formation in lakes and ocean, which promotes aeration of water
• Strong wind causes soil erosion and reduces soil fertility
• Increases the rate of transpiration
• Helps in pollination in anemophilous plants
• It also helps in dispersal of many fruits, seeds, spores, etc.
• Strong wind may cause up-rooting of big trees
• Unidirectional wind stimulates the development of flag forms in trees.

Question 3.
Write about important edaphic factors which affect vegetation of plants ?
Answer:
The important edaphic factors which affect vegetation are as follows:
1. Soil moisture:
Plants absorbs rain water and moisture directly from the air.

2. Soil water:
Soil water is more important than any other ecological factors affecting the distribution of plants. Rain is the main source of soil water. Capillary water held between pore spaces of soil particles and angles between them is the most important form of water available to the plants.

3. Soil reactions:
Soil may be acidic or alkaline or neutral in their reaction. pH value of the soil solution determines the availability of plant nutrients. The best pH range of the soil for cultivation of crop plants is 5.5 to 6.8.

4. Soil nutrients:
Soil fertility and productivity is the ability of soil to provide all essential plant nutrients such as minerals and organic nutrients in the form of ions.

5. Soil temperature:
Soil temperature of an area plays an important role in determining the geographical distribution of plants. Low temperature reduces use of water and solute absorption by roots.

6. Soil temperature:
The spaces left between soil particles are called pore spaces which contains oxygen and carbon-di-oxide.

7. Soil organisms:
Many organisms existing in the soil like bacteria, fungi, algae, protozoans, nematodes, insects, earthworms, etc. are called soil organisms.

Question 4.
What is topography? What are the various topographic factors involves (or) influence on the climate of any area ?
Answer:
The surface features of earth are called topography. Its factors include, latitude, altitude, direction of mountain, steepness of mountain.

a. Latitudes and altitudes:

• Latitudes represent distance from the equator. Temperature values are maximum at the equator and decrease gradually towards poles.
• So different types of vegetation occur in latitude.
• Height above the sea level forms the altitude. At high altitudes
• The velocity of wind remains high. Temperature and are pressure – decrease While humidity and intensely of light increases.
• Due to these factors vegetation at difference altitudes varies showing distinct zonation.

b. Direction of mountain:
North and south faces of mountain (or) hill possess different types of flora and fauna because thev differ in their humidity, rainfall light intensity, light duration and temperature regions.

c. Steepness of the mountain:

• The steepness of the mountain (or) hill allows the rain to run off.
• As a result the loss of water causes water deficit and quick erosion of the top soil resulting in poor vegetation.
• On the other hand the plains and valley are rich in vegetation due to the slow drain of surface water and retention of water in the soil.

Question 5.
What are various biotic factors which is exist between the organism ?
Answer:
The interactions among living organisms such as plants and animals are called biotic factors.

Positive interactions:
When both (or) one the participating species are benefited. (Eg.) Mutualism and commen¬salism.

Mutualism:

• It is an interaction between two species of organisms in which both are benefitted from the obligate association.
• Lichens is a mutual association of an algae and a fungus.
• The alga is usually green alga (or) blue green alga. The fungus is an ascomycete (or) basidiomycetes.
• It is believed that alga contributes organic food from photosynthesis and the fungus is able to absorb water and mineral salts.
• The fungus can also conserve water and this enables lichens to grow in extreme dry conditions where no other plants can exist.

Nitrogen fixation:

• Rhizobium (Bacterium) forms nodules in the roots of leguminous plants and lives symbiotically.
• The Rhizobium obtains food from leguminous plant and in turn fixes atmospheric nitrogen into nitrate, making it available to host plants.
• Example: Water fern (Azolla) and Nitrogen fixing cyanobacterium (Anabaena)
• Anabaena present in coralloid roots of cycas

Commensalism:
Many orchids ferns, lianas, money plant usnea (lichen) are some of the examples of epiphytes.
These plants which are found on other plant and growing without harming them are called epiphytes.

Negative interactions:

a. Predation:
It is an interaction between two species, one of which captures, kills and eats up the other. The species which kills is called a predator and the species which is killed is called a prey. The predator is benefitted while the prey is harmed.

Examples:
A number of plants like Drosera (Sun dew Plant), Nepenthes (Pitcher Plant), Dionaea (Venus fly trap), Utricularia (Bladder wort) and Sarracenia are predators which consume insects and other small animals for their food as a source of nitrogen. They are also called as insectivorous plants.

Many herbivores are predators. Cattles, Camels, Goats etc., frequently browse on the tender shoots of herbs, shrubs and trees. Generally annuals suffer more than the perennials. Grazing and browsing may cause remarkable changes in vegetation. Nearly 25 percent of all insects are known as phytophagous(feeds on plant sap and other parts of plant)

Question 6.
Write the morphological adaptations of xerophytes.
Answer:
Morphological Adaptations:
In root:

• Root system is well developed and is greater than that of shoot system.
• Root hairs and root caps are also well developed.
• In Xerophytic plants with the leaves and stem are covered with hairs are called tricho- phyllous plants.
• Eg: Cucubits (Melothria andMukia)

In stem:

• Stems are mostly hard and woody. They may be aerial or underground.
• The stems and leaves are covered with wax coating or covered with dense hairs.
• In some xerophytes all the internodes in the stem are modified into a fleshy leaf structure called phylloclades (Opuntia)
• In some of the others single or occasionally two internodes modified into fleshy green structure called cladode (Asparagus)
• In some the petiole is modified into a fleshy leaf like structure called phyllode (Acacia melanoxylon)

a) A succulent xerophyte: Phylloclade – opuntia
b) Non succulent: Perennial – Capparis
c) Cladode of Asparagus
d) Phyllode – Acacia
aquatic and terrestrial modes of life. They grow in shallow water.
Examples: Ranunculus, Typha and Sagittaria.

Question 7.
Write anatomical and physiological adaptation of hydrophytes ?
Answer:
Anatomical adaptations:

• Cuticle is either completely absent or if present it is thin and poorly developed
• Single layer of epidermis is present
• Cortex is well developed with aerenchyma
• Vascular tissues are poorly developed. In emergent forms vascular elements are well developed.
• Mechanical tissues are generally absent except in some emergent forms. Pith cells are sclerenchymatous.

Physiological adaptations of hydrophytes:

• Hydrophytes have the ability to withstand anaerobic conditions.
• They possess special aerating organs.

Question 8.
What are epiphytes ? What are its morphologic adaptations?
Answer:
Epiphytes:
Epiphytes are plants which grow perched on other plants (Supporting plants). They use the supporting plants only as shelter and not for water or food supply.
Orchids, Lianas, Hanging Mosses and Money plant.

Morphological adaptations:

• Root system is extensively developed. These roots may be of two types. They are Clinging roots and Aerial roots.
• Clinging roots fix the epiphytes firmly on the surface of the supporting objects.
• Aerial roots are green coloured roots which may hang downwardly and absorb moisture from the atmosphere with the help of a spongy tissue called velamen.
• Stem of some epiphytes are succulent and develop pseudo bulb or tuber.
• Generally the leaves are lesser in number and may be fleshy and leathery Myrmecophily is a common occurrence in the epiphytic vegetation to prevent the predators.

Question 9.
Write about anatomical and physiological adaptations of epiphytes ?
Answer:
Anatomical adaptations:

• Multilayered epidermis is present. Inner to the velamen tissue, the peculiar exodermis layer is present.
• Presence of thick cuticle and sunken stomata greatly reduces transpiration.
• Succulent epiphytes contain well developed parenchymatous cells to store water.

Physiological adaptations:
Special absorption processes of water by velamen tissue.

Question 10.
Write about anatomical and physiological adaptations of halophytes ?
Answer:
Anatomical adaptations:

• Epidermal cells of stem is heavy cutinized, almost squarish and are filled with oil and tannins.
• Star’ shaped sclereids and ‘H’ shaped heavy thickened spicules that provide mechanical strength to cortex are present in the stem.
• The leaves may be dorsiventral or isobilateral with salt secreting glands. Physiological adaptations:
• High osmotic pressure exists in some plants
• Seeds germinate in the fruits of mother plant itself (Vivipary).

Question 11.
What are the adaptations found in hy drochory plants with example ?
Answer:
Dispersal of seeds and fruits by water usually occurs in those plants which grow in or near water bodies. Adaptation of hy drochory are

• Obconical receptacle with prominent air spaces. Example: Neliimbo.
• Presence of fibrous mesocarp and light pericarp. Example: Coconut.
• Seeds are light, small, provided with aril which encloses air. Example: Nymphaea.
• The fruit may be inflated. Examples:

Heritiera littoralis.

• Seeds by themselves would not float may be carried by water current.
  Example: Coconut.

Question 12.
Write about the various adaptation of wind dispersal plant (or) anemochory plants.
Answer:
The individual seeds or the whole fruit may be modified to help for the dispersal by wind. Wind dispersal of fruits and seeds is quite common in tall trees.

• Minute seeds: Seeds are minute, very small, light and with inflated covering. Example: Orchids.
  Wings : Seeds or whole fruits are flattened to form a wing. Examples: Maple, Gyrocarpus, Dipterocarpus and Terminalia
• Feathery Appendages : Seeds or fruits may have feathery appendages which greatly increase their buoyancy to disperse to high altitudes. Examples: Vernonia and Asclepias.
• Censor mechanisms : The fruits of many plants open in such a way that the seeds can escape only when the fruit is violently shaken by a strong wind. Examples: Aristolochia and Poppy.

Question 13.
What is autochory? Write about its explosive mechanism for dispersal of fruits and seeds.
Answer:

• Some fruits burst suddenly with a force enabling to throw seeds to a little distance away from the plant. Autochory shows the following adaptations.
• Mere touch of some plants causes the ripened
  fruit to explode suddenly and seeds are thrown out with great force. Example: Impatiens (Balsam), Hura.
• Some fruits when they come in contact with water particularly after a shower of rain, burst suddenly with a noise and scatter the seeds. Examples: Ruellia and Crossandra.
• Certain long pods explode with a loud noise like cracker, scattering the seeds in all directions. Example: Bauhinia vahlii (Camel’s foot climber)
• As the fruit matures, tissues around seeds are converted into a mucilaginous fluid, due to which a high turgor pressure develops inside the fruit which leads to the dispersal of seeds.
• Example: Ecballium elaterium (Squirting cucumber) Gyrocarpus and Dipterocarpus.

Question 14.
Explain the role of wind as a vital Ecological
Answer:

• Air in motion is called wind. It is also vitral ecological factor.
• The atmospheric air contains a number of gases, particles and other constituents.
• The composition of gases in atmosphere is as follows
• Nitrogen – 78%, Oxygen – 21%., Carbon-di¬oxide – 0.03%., Argon and other gases – 0.93%.
• The other components of wind are water vapour, gaseous pollutants, dust, smoke particles, microorganisms pollen grains, spores etc.
• Anemometer is the instrument used to measure the speed of wind.

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th English Guide Pdf Poem 5 Everest is Not The Only Peak Text Book Back Questions and Answers, Summary, Notes.

Tamilnadu Samacheer Kalvi 11th English Solutions Poem 5 Everest is Not The Only Peak

11th English Guide Everest is Not The Only Peak Text Book Back Questions and Answers

A. Based on your understanding of the Poem, answer the following questions in a sentence or two each:

Question 1.
Which line is repeated in the poem? What is the effect created by this repetition?
Answer:
The line, “We are proud and feel so tall” is repeated often in the poem. This establishes beyond a doubt the poet’s pride in the dignity of labor and pride of hard work experienced by ordinary folks in life.

Question 2.
Who are the deserving ones?
Answer:
Men who are deemed in their duty and mission in life are the deserving ones.

Question 3.
Which quality does the speaker wish to nourish? What is his mission?
Answer:
The speaker wishes to nourish love to mankind. The poet loves to nourish the ones who nourish the world. His mission is to bless and praise the deserving ones.

Question 4.
Which path should we follow in life?
Answer:
We should be happy and proud of our position and we should follow this path in life.

Question 5.
What does ‘Everest’ in the title stand for?
Answer:
‘Everest’ means the greatest achievement in life or the highest point one can reach in life.

Question 6.
What does hillock ‘refer to in the line Every hillock has a summit to boast!’?
Answer:
Hillock refers to whatever position one holds.

Question 7.
Why does the speaker say “Everest is not the only Peak”?
Answer:
Everyone is not made to be a mountain climber or a captain. Each one has an important role in this life however small it may appear to be. The poet respects every small achievement in every walk of life. So, he says, “Everest is not the only peak”.

Question 8.
What does the ladder symbolize?
Answer:
The ladder symbolizes truth and standing on their own.

B. Read the given lines and answer the questions that follow:

1. Our nature it is that whatever we try
We do with devotion deep and true

Question a.
Who does ‘we’ refer to?
Answer:
‘We’ refers to human beings (virtuous people)

Question b.
How should we carry out our duties?
Answer:
We must do our duty with sincerity and deep devotion.

2. Defeat we repel, courage our fort:

Question a.
How do we react to defeat?
Answer:
We hate to face defeat.

Question b.
Which is considered as our stronghold?
Answer:
Courage is considered as our stronghold.

3. We are proud of the position we hold
humble as we are,

Question a.
What is the speaker proud of?
Answer:
The speaker is proud of the position he holds.

Question b.
How is the speaker both humble and proud?
Answer:
He is happy with his position.

Question c.
Pick out the alliteration in these lines.
Answer:
Proud, position; hold, humble

4. He, who does not stop, is a king we adore.
We bow before competence and merit.

Question a.
Who is adored as a king?
Answer:
We adore as a king who does not sacrifice his virtues or dignity for success.

Question b.
What is the figure of speech?
Answer:
Metaphor

5. Honour is a property, common to all
Indignity and pride no one needs to be poor.

Question a.
Who is considered rich?
Answer:
Dignity and pride are considered rich

Question b.
What is their asset?
Answer:
Honour is their asset.

Figure of Speech:

Alliteration:

1. ‘We do with devotion deep and true’
   Do – devotion – deep
2. ‘We are proud of the position we’
   Proud – position
3. A life that knows no kneeling and bending’
   Knows – kneeling
4. ‘We deem it our duty and mission in life
   Deem – duty

Rhyming words and Rhyming scheme in the 1st stanza:

• Tall – small – Rhyming words,
• aabc – scheme

C. Answer the following questions ina paragraph of 100 – 150 words:

Paragraph:

The poem does not focus on the destination but the journey towards it – Discuss:

The poet kulothungan says that we should do our work with dull determination and honesty in our activity/duty.

“We do with devotion deep and true”
The poet wishes to nourish the quality of doing his work with full dedication and never give it up.

“Never shall we fail in what we commit, Shall nourish the ones that nourish the world”
Poet says that we should not depend on others but stand on our own legs. That is the ladder for the man to reach the highest position in life.

“The ones that are true and stand on their own are really the ladder for the rise of man”
The poet kulothungan says us to be the happiest. There is some work for everyone to do in this world. The job which is to be completed is not very far away. If we cannot be the highway but we can be the trail.

“Everest is not the only peak,
every hillock has a summit to boast!”
The size doesn’t matter for winning and losing, what matters is the best whatever you are.

Explain the following with reference to the context:

I) ’We do with devotion deep and true’

Reference:
This line is taken from Poem – “Everest is not the only peak”, Poet – “Kulothungan”.
Context:
Here the poet talks about determination.
Explanation:
Poet says that we should do our work with full determination and be honest in our activity.

II) The ones that are true and stand on their own.
Are really the ladder for the rise of Man.

Reference:
This line is taken from Poem – “Everest is not the only peak”, Poet – “Kulothungan”.
Context:
Here the poet talks about the unaided life.
Explanation:
Poet says that we should not depend on others but stand on our own legs. That is the ladder for the man to reach the highest position in life.

கவிஞரைப் பற்றி:

பேராசிரியர் வி.சி. குழந்தைசாமி (1929-2016) ஒர சிறந்த பொறியியல் வல்லுனர். நீர்மேலாண்மை துறையில் சிறந்து விளங்கினார். சிறந்த எழுத்தாளர், கல்வியாளர், இலக்கியம், கல்வி என பல துறைகளில் கால் பதித்தவர். இவர் குலோத்துங்கன் என்ற புனைப்பெயரில் தன் கவிதைகளை எழுதியுள்ளார்.

1988ம் ஆண்டு தனது “வாழும் வள்ளுவம்” என்ற நூலுக்கு சாகித்திய அக்காடமி விருது பெற்றவர். 1999-ல் தமிழக அரசு வழங்கிய திருவள்ளுவர் விருதைப் பெற்றார். இவர் மனித வளமேண்பாடு பற்றிய கவிதைகளை அதிகம் எழுதியுள்ளார்.

கவிதையைப் பற்றி:

மனித திறமைகள் சிறியதாயினும், செயல்கள் குறைவாயினும் அதை நினைத்து நாம் பெறுமை பட வேண்டும். சாதனைகளும், புகழும் மட்டுமே வாழ்க்கையல்ல. பிறருக்கு துன்பம் தராத, பொய்வேசம் போடாதா வாழ்க்கையே சிறந்த வாழ்க்கை தோல்வி அடைந்தவன் திறமையில்லாதவன் அல்ல. சாதிப்பவன் எல்லாம் திறமைசாலியும் அல்ல. அனைவருமே அவரவர் வாழ்வில் சாதனையாளர்களே.

Everest is Not The Only Peak Summary in Tamil

உயரமாய் ஓங்கி உயர்ந்து வளர்ந்து நிற்பதில் யாம் பெருமை கொள்கிறோம்.
கடவுளுடைய அனுக்கிரகம் குறைவாக இருந்தபோதிலும் கூட
இயற்கையாகவே யாம் என்னதான் முயற்சித்தாலும்
அதை உண்மையான ஆழமான பக்தி முயற்சியுடன் செய்வோம்.

முற்றுகையை ஒவ்வாமையாக தைரியத்தைக் கோட்டையாக
ஆனால் கைப்பற்றுவது மற்றும் செய்வது இல்லை
மற்றவர்களை அன்பு செய்வதை இலாபமாக கருதி
ஓங்கி உயர்ந்து வளர்ந்து நிற்பதில் யாம் பெருமை கொள்கிறோம்.
இதை யாம் ஒரு கடமையாகவும், வாழ்வின் ஒரு திருப்பணியாகவும்
வாடி வருந்துவோரை ஆசிர்வதிக்கவும் துதிக்கவும்
யாம் செய்வதில் இருந்து சற்றும் தவறாமல்

உலகை உயர்த்துவதிலே உறுதியாய் நிற்கிறோம்.
யாம் தற்போது இருக்கின்ற நிலையைப் பார்த்து பெருமை கொள்கிறோம்
பணிந்து கொண்டு நிற்கிறோம் –
எங்களின் வாழ்வுப்பாதையை எண்ணி பெருமிதம் கொள்கிறோம்

மதிப்பு மிக்க எங்களின் பாதை
ஒரு வாழ்வில் வளையும் குறுகலானதும் இல்லாததை நினைத்து
ஓங்கி உயர்ந்து வளர்ந்து நிற்பதில் யாம் பெருமை கொள்கிறோம்
இமயம் ஒரு உச்சி அல்ல

அனைத்து உச்சிகளும் துதித்துப் பாடவே
நீங்கள் கொடுக்கின்ற உயரத்தைப் பற்றி கவலை இல்லை
மேலிருந்து கீழே இறங்கி வருபவனே அரசனாக யாம் கொள்வோம்.
உண்மைக்கும் நீதிக்கும் முன்னால் யாம் தலை வணங்குவோம்

உண்மையான காலிலே நிற்கும் ஒருவனை
யாம் ஒரு ஏணியாக மதித்து
மனிதனின் முழு வளர்ச்சிக்கு
எல்லோருக்கும் பொதுவாக, போற்றுவதற்கு உரிய ஒரு சொத்தாக

வறுமையிலும் பெருமையிலும் யாம் ஒரு ஏழை அல்ல
ஓங்கி உயர்ந்து வளர்ந்து நிற்பதிலே யாம் பெருமை கொள்கிறோம்.

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th English Guide Pdf Poem 4 Macavity – The Mystery Cat Text Book Back Questions and Answers, Summary, Notes.

Tamilnadu Samacheer Kalvi 11th English Solutions Poem 4 Macavity – The Mystery Cat

11th English Guide Macavity – The Mystery Cat Text Book Back Questions and Answers

A. Based on your understanding of the poem, answer the following questions in a sentence or two:

Question i.
What is Macavity’s nickname?
Answer:
Macavity’s nickname is “ Hidden Paw”.

Question ii.
Why is the flying squad frustrated?
Answer:
Macavity is too clever to leave any evidence of his guilt. He is a puzzle for the flying squad who is specialized in investigating the crime. So the flying squad is frustrated.

Question iii.
Which law does Macavity break?
Answer:
Macavity breaks human law and also the law of gravity.

Question iv.
What makes the fakir stare in wonder?
Answer:
Macavity’s levitation is so powerful that it causes a fakir to stare bewildered.

Question v.
Describe Macavity’s appearance.
Answer:
Macavity is veiy tall and slim. His eyes are sunken. His brow is deeply lined. His head is highly domed. His coat is dusty and whiskers unkempt.

Question vi.
Where can you encounter Macavity?
Answer:
We can encounter Macavity in a by-street or in the square.

Question vii.
Why does the poet say Macavity is ‘outwardly’ respectable?
Answer:
The poet says that Macavity is respectable ‘outwardly’ because all his stealthy, criminal activities betray his vile nature.

Question viii.
Who does the secret service suspect when a loss is reported?
Answer:
The secret service suspects Macavity when a loss is reported.

Question ix.
What is Macavity expected to be doing after committing a crime?
Answer:
Mungojerrie and Griddlebone are examples of wicked cats.

Question x.
Mention any two qualities of Macavity.
Answer:
Macavity possesses supernatural powers which allow him to levitate up in the air. He is so confident in his manner that whenever the crime is discovered, he disappears without leaving a single trace.

Question xi.
Which two characters does the poet refer to as examples of wicked cats?
Answer:
Macavity is too clever to be caught and he is nowhere near at the crime spot. He is an enigmatic figure to even the specialized detective agencies.

Question xii.
Why is Macavity called the napoleon of crime’?
Answer:
Napoleon of crime means the commanding leader of criminals. Here the Macavity is the commanding leader for other wicked cats (Mungojerrie and Griddle bone). So Macavity is called the ‘Napoleon of crime’.

B) Read the poem and complete the summary using the words given in the box:

‘Macavity — The Mystery Cat’ is a humorous poem, where the poet T.S. Eliot describes the mysterious (a) _______ of a shrewd vile cat. He commits a crime at every possible opportunity. He is an elusive master (b) _______ who leaves no evidence after he commits a crime. Even the Scotland Yard, the London (c) _______ agency is unable to arrest him. The Flying Squad is (d) ________ because every time they rush to the crime spot to seize Macavity, he is not there. He breaks the human law as well as the law of (e) _______. He baffles even a (f) ________ with his powers of levitation. Macavity appears tall and thin with (g) _______ eyes. He is always preoccupied with some serious (h) _______. His coat is dusty and his (j) _______are unkempt. Macavity is a (j) ________ in the guise of a cat. He appears to be outwardly (k) _________ but his actions disprove it. Macavity loots the (l) _______, ransacks the jewel-case, and breaks the (m) _______ glass but the wonder of wonders he is not to be found anywhere there. He is always a mile away from the scene of the crime, happily relaxing or doing difficult (n) ____________ sums. He is clever at making up an (o) _______ every time he plots a crime. All the notorious cats are nothing but the (p) ________ of Macavity, the Napoleon of Crime.

Answers:
(a) Qualities
(b) Criminal
(c) Detective
(d) Desperate
(e) Gravity
(f) Fakir
(g) Sunken
(h) Thought
(i) Whiskers
(j) Devil
(k) Respectable
(l) Larder
(m) Greenhouse
(n) Division
(o) Alibi
(p) Agents

Paragraph:

1. What are the mysterious ways in which Macavity acts?
2. Describe the appearances and qualities of Macavity?

In T.S Eliot’s poem, ‘Macavity: The mystery cat, he describes the mysterious qualities of a cat of villainous characters.

‘Macavity’s a ginger cat, he’s very tall and thin:
Macavity is a tall and thin cat who is always up to some crime. He is too clever to leave any evidence of his guilt.

“He’s the bafflement of Scotland Yard, the flying squad’s despair”:
He is an enigma to every detective agency in the world including. Scotland Yard and flying squad who are specialized investigating crime.

“It must have been Macavity! But he’s a mile away”:
There is never enough proof to arrest and he’s a mile away from all crime spots.

“He’s broken every human law; he breaks the law of gravity”:
Not only does he breaks the human law but also breaks the law of gravity.

“His brow is deeply lined with thought, his head is highly domed”
His coat is dusty from neglect, his whiskers are uncombed.
He always moves his head from side to side, with movements like a snake.

His brows are deeply lining as a result of continuous planning of the crime. Macavity has sunken eyes and “his head is highly domed”. He never combs his whiskers His movements resemble that of a snake. He spends his time plotting for the criminal acts and how to carry them out. The poet accuses, Macavity of his behaviour, such as stealing milk but also holds him responsible for major crimes.

‘For he’s a fiend in feline shape, a monster of depravity’:
The cat is a devil in disguise and he is a monster of wickedness. He has been suspected of stifling Pekes, Vandalism, theft, cheating of cards, and spying. He has also controlled an organized crime with Mungojerrie, Griddle Bone among the members. So the poet says that all the notorious cats are nothing but the agents of Macavity, the Napoleon of crime.

“Are nothing more than agents for the cats who all the time Just controls their operator’s the Napoleon of Crime”?

Read the given lines and answer the questions that follow:

i) Macavity’s a Mystery Cat: he’s called the Hidden Paw.

Question a.
Does the poet talk about a real cat?
Answer:
No, the poet talks about an imaginary character.

Question b.
Why is he called the Hidden Paw?
Answer:
He is called the Hidden Paw as he is the criminal mastermind who disregards the law.

ii) He’s the bafflement of Scotland Yard, the Flying Squad’s despair:
For when they reach the scene of crime Macavity s not there!

Question a.
What is ‘Scotland yard’?
Answer:
Scotland Yard is the world-famous headquarters of the London metropolitan police service known for quick investigation of crime and nabbing the criminal in record time.

Question b.
Why does the flying squad feel disappointed?
Answer:
Macavity is too clever to be caught and he is nowhere near at the crime spot. So the flying squad feels disappointed.

iii) He sways his head from side to side, with movements like a snake; And when you think he’s half asleep, he’s always wide awake…

Question a.
Explain the comparison made here.
Answer:
Macavity moves his head from side to side and his body movement is compared to a snake.

Question b.
What does he pretend to do?
Answer:
He pretends to be asleep.

iv) For he’s a fiend in feline shape.
A monster of depravity.

Question a.
How is the cat described in this line?
Answer:
The cat is a devil in disguise of a cat.

Question b.
Explain the phrase ‘monster depravity’
Answer:
‘Monster of depravity’ means he is a monster of wickedness.

v) And his footprints are not found in any file of Scotland yard’s

Question a.
What seems to be a challenge for the Scotland yard?
Answer:
Macavity s footprints are never to be found in any file of the Scotland yard’s.

Question b.
Why do they need his footprints?
Answer:
They need his footprints to catch him.

vi) ‘It must have been Macavity! But he’s a mile away.

Question a.
What is Macavity blamed for?
Answer:
Macavity is blamed for breaking the greenhouse glass and for theft. Also when the milk goes missing.

Question b.
Where is he?
Answer:
He is a mile away from the scene of the crime.

vii) There never was a cat of such deceitfulness and suavity.

Question a.
Which cat is being talked of here?
Answer:
Macavity is being talked.

Question b.
How is he different from the rest?
Answer:
He is different from the rest by his dishonesty, cunningness but be pretends to be innocent.

E. Explain the following lines with reference to the context:

I. His powers of Levitation would make a fakir stare’

Reference:
This line is taken from the Poem “Macavity-The Mystery Cat”, Poet – “T.S Eliot”.
Context:
Here the poet talks about the power of Macavity.
Explanation:
The poet says that his levitation is so powerful that it causes a fakir to stare bewildered.

II. ‘And when you think he’s half asleep, he’s always wide awake.

Reference:
This line is taken from the Poem “Macavity-The Mystery Cat”, Poet – “T.S Eliot”.
Context:
Here the poet talks about the pretending sleep of Macavity.
Explanation:
Macavity is a clever fellow. When you think he is sleeping, he is wide awake in fact.

III. And his footprints are not found in any file of Scotland yard’s

Reference:
This line is taken from the Poem “Macavity-The Mystery Cat”, Poet – “T.S Eliot”.
Context:
Here the poet talks about the great escapism of Macavity.
Explanation:
Macavity footprints are never to be found in any file of the Scotland yards. When they try to find him he is a mile away from the scene of the crime.

IV. There may be a scrap of paper in the hall or on the stair
But it’s useless to investigate

Reference:
This line is taken from the Poem “Macavity-The Mystery Cat”, Poet – “T.S Eliot”.
Context:
The poet talks about the mastermind of the cat.
Explanation:
When the foreign office’s Treaty is not found or the Admiralty Treaty is not found or the Admiralty loses some plans and drawing. It is useless to investigate as they all know that the mastermind behind this act is undoubtedly Macavity’s.

V. He always has an alibi, and one or two to spare.

Reference:
This line is taken from the Poem “Macavity – The Mystery Cat”, Poet – “T.S Eliot”.
Context:
Here the poet talks about making up an alibi.
Explanation:
The poet says that there has never been a cat of such deceitfulness and tactfulness. Macavity is always ready with an alibi or two and when the crime is discovered, Macavity is not there.

F. Eliot has many figures of speech to present the poem to the readers in an interesting way. He has attributed the human qualities of a cat in this poem:

Question i.
Identify the literary devices used in the following lines: (Figure of Speech)
Answer:

• He sways his head from side to side, with movements like a snake – simile
• They say he cheats at cards. – metaphor/Personification
• Macavity, Macavity there’s no one like Macavity -Repetition

Question ii.
Give four instances where the poet has used alliteration in the poem.
Answer:
Alliteration in the poem

1. “His brow is deeply lined with thought, his head is highly domed.”
   Deeply – domed.
2. “For he’s fiend in feline shape, a monster of depravity.”
   fiend – feline.
3. “Or when the milk is missing, or another Peke’s been stippled.”
   Milk – missing.
4. “And his footprints are not found in any file of Scotland yard’s.”
   Foot prints – found — file

Question iii.
What is the rhyme scheme used in the poem?
Answer:
aa, bb

Question iv.
Pick out all the pairs of rhyming words used in the poem.
Answer:
Rhyming words:

1. Paw – law
2. Despair – there
3. Macavity – gravity
4. Stare – there
5. Air – there
6. Thin – in
7. domed – uncombed
8. Snake – awake
9. Macavity – depravity
10. Square – there
11. Cards – yard’s
12. Rifled – stifled
13. Repair – there
14. Astray – way
15. Repair – there
16. Stair – there
17. Say – away
18. Thumbs – sums
19. Macavity – suavity
20. Spare – there
21. Known – griddlebone
22. Time – crime.

H. Speaking activity:

b) Meaning of the proverb:
What is proverb Expansion?

A proverb is a statement, accepted by all people of a particular community over the generations. ‘Expansion’ means developing and enlarging the idea or a thing. ‘Proverb Expansions’ means enlarging the idea confined in a proverb into a paragraph.
Hints:

1. Be thorough with the exact meaning of the proverb.
2. Then proceed to expand the proverb with examples and the relevant details.
3. Arrange your ideas in order, that is relevant.
4. Avoid everything that is irrelevant.
5. Explain the meaning of the proverb in plain language.
6. Avoid ‘Cliche’ and stereotyped uninteresting phrases.
7. Make paragraphs of equal length and size.

Example:
When the mouse laughs at the cat, there is a hole nearby. Explain the meaning of this statement to your friends.

Meaning:
The meaning of this proverb is that we act tougher when we know we have a backup. When our backgrounds is strong we seem to be bolder in action.

Additional Exercises:

Explain the meaning of the following proverbs:

1) ‘Slow and steady wins the race’
Consistency and steadiness can achieve massive success even if slow. A person with average talent can achieve success through continuous efforts. One can overcome difficulties through constant effort in the right direction.

2) Don’t judge a book by its cover
Things are not always what they seem. This proverb teaches you not to make judgments about other people because of how they look or dress. A book with a boring or plain over could be amazing. The same is true with people. A person might look like an athlete or fool, but there is probably a lot more to them than clothes suggest.

3) Strike while the iron is hot
This old expression comes from the days of blacksmiths. To shape the metal, the blacksmith would have to beat it with a hammer. Iron is easier to work with when it’s hot. This proverb means you should take advantage of the moment. If an opportunity presents itself to you, take it! Take action because the change may not come again.

4) Too many cooks spoil the broth
“Too many cooks in the kitchen.” This is a well-known experience – a lot of people all trying to work in a kitchen around a small table or stovetop will make a mess and ruin the food. This proverb talks about the trouble of too many people trying to do the same thing at once.

5) Honesty is the best policy
Lying a lot can be difficult because you might forget your lies, Soon enough, someone will find out you are lying. Even if no one ever finds out, you will feel guilty for not telling the truth. If you are honest and tell the truth, people will believe you and respect you. You will earn their trust and sleep well at night.

C. Compose a poem:

c) Compose your own limericks on an elephant, a peacock, and a butterfly. Read it out to your class.

Elephant
I love Elephant
Its eyes are tiny
But they are shiny
Its trunk is long
But it is very strong
It moves slowly
But it is brain ‘A peacock’
Joy is a peacock-it’s beauty so rare;
A rainbow of colors that vibrantly flare.
After the train, brightly they come out.
Into a far-like form, uniquely it creates.
Never forget, this vision, joyfully it illuminates.
A butterfly
I saw a butterfly
It wings so high
This colourful fly
A treat to my eye.

கவிஞரைப் பற்றி:

தாமஸ் ஸ்டேனஸ் எலியட் (1888-1965) மிகச்சிறந்த கட்டுரையாளர். இவர் இருபதாம் நூற்றாண்டின் மிகச்சிறந்த விமர்சகர், நாடக ஆசிரியர், கவிஞர் ஆவார். இவர் அமேரிக்காவில் உள்ள ஹார்வர்ட் பல்கலைக்கழகத்தின் மாணவர் சமஸ்கிருதம் கற்றதன் மூலம் இந்திய தத்துவயியலையும் கற்றார்.

” The Wasteland”, ” Love Song of I Alfred Prufrock”, “Ash Wednesday”, Four Qartets, “Journey of the magi”, “After strange gods”, Namingofcats ஆகியவை இவரின் சிறந்த படைப்புகள். இவருக்கு 1948ம் ஆண்டு இலக்கியத்திற்கான நோபல் பரிசு வழங்கப்பட்டது.

கவிதையைப் பற்றி:

கவிஞர் இந்த கவிதையில் ஒரு வீட்டில் இருந்த சுட்டித்தனமான பூனையின் செயல்பாடுகளை விவரிப்பதாக எழுதியுள்ளார். அப்பூனையின் பெயர் மெக்காவிட்டி. பூனைகள் நாம் காணமுடியாததை காணக்கூடிய, நாம் செய்ய அச்சப்படுகிற இருடத்திற்கும் செல்லக் கூடிய மர்மமான ஆற்றல் கொண்டவை.

அதைப்போல இக்கவிதையில் பேசப்படும் பூனையும் யாருடைய கையிலும் சிக்காமல் பல சேட்டைகளை செய்து வருவதாகவும், திருட்டுத்தனங்கள் செய்வதாகவும், ஆனால் திருட்டு நடந்த இடத்திற்கு காவல்துறை பிடிக்க சென்றால் அந்த இடத்தில் அந்த பூனை இருக்காது. இக்கவிதையில் மெக்காவிட்டி பூனையின் மர்மமான குண நலன்களைப் பற்றி தெளிவாகவும், நகைச்சுவையாகவும் கூறுகிறார்.

Macavity – The Mystery Cat Summary in Tamil

மெக்கவிட்டி மர்மமான பூனை;
அவன் மறைவான பாதம் என்று அழைக்கப்படுவான்.
ஏனெனில் அவன் சட்டத்தை மதிக்காத முதன்மை குற்றவாளி
Scotland yard – ன் குழப்பமாகவும்;
Flying squad-ன் பிடிபடாத குற்றவாளி,
அவர்கள் குற்றம் நடந்த இடத்திற்கு செல்லும் போது
அங்கு மெக்கவிட்டி இருப்பது இல்லை.
Macavity அவன் போல் யாரும் இல்லை .

மனித சட்டத்தையும், புவி ஈர்ப்பு விசையையும் உடைத்தெரிந்தான்
அவன் தாவுதல் ஆற்றல் வாய்ந்ததாக இருக்கும்.
நீங்கள் குற்றம் நடந்த இடத்திற்கு செல்லும் போது,
Macavity அங்கு இருப்பது இல்லை.
நீங்கள் அடித்தளத்தில் அவனைத் தேடலாம்;
நீங்கள் காற்றிலும் அவனை தேடலாம்.

ஆனால் நான் மறுபடியும் மறுபடியும் சொல்கிறேன்
Macavity ஒரு எச்சரிக்கையான (ginger) பூனை
அவன் மெலிந்தும் மற்றும் உயரமாகவும் இருப்பான்.
நீங்கள் அவனை பார்த்தவுடன் அவனை அறிவீர்கள்;
அவனது கண்கள் மூழ்கி இருக்கும்.
அவனது புருவங்கள் ஆழ்ந்த சிந்தனை கொண்டவை;
அது மிகவும் ஆதிக்கம் செலுத்தும்.

அவனது உடல் முழுவதும் தூசி படிந்திருக்கும்
அவனது மீசைகள் சீராக இருக்காது.
அவனது தலையை பாம்பைப் போல் அங்கும் இங்கும் ஆட்டுவான்.
நீங்கள் அவன் கொஞ்சம் தூங்கி இருப்பான் என்று நினைப்பீர்கள்,
ஆனால் நன்று விழித்திருப்பான்.
Macavity யாரும் அவன் போல் இல்லை
பூனை (feline) வடிவம் கொண்ட எதிரி (fiend),
தீய பண்புகள் (depravity) கொண்ட அரக்கர்.

அவனை நீங்கள் தெருவில் சந்திக்கலாம்,
அவனை square கூட பார்க்கலாம்.
ஆனால் ஒரு குற்றம் கண்டறிந்தால்,
Macavity அங்கு இருப்பதில்லை!
அவனது வெளிப்படுத்தல் மதிக்கக்கூடியதாக இருக்கும்
(அவர்கள் அவன் விலை ஏமாற்றுவதை கூறுவார்கள்)
அவனது காலடி தடங்கள் Scotlands எங்கும் காணப்படுவது இல்லை.

முழு அலமாரியும் (Larder’s) சூறையாடப்படும் போது,
நகைகள் எல்லாம் கொள்ளையிடப்படும் போதும்
பால் எல்லாம் காணாமல் போக, ஒரு பெக்கினி நாயை (Peke’s) அடக்கப்படும் போது
அல்லது கிரீன்ஹவுஸ் கண்ணாடிகள் உடையும் போது,
மரப்பட்டையின் பழைய பழுது
இதில் திகைக்கக்கூடிய விஷயம் என்ன என்றால்!

Macavity அங்கு இருப்பதில்லை!
வழிகாட்டிய ஒப்பந்தத்தை வெளிநாட்டு அலுவலகம் கண்டறியும் போது
அல்லது அரசு பணிகளின் திட்டங்கள் மற்றும் படங்கள் காணாமல் போகும் போது,
சில துண்டு காகிதங்கள் ஹால் மற்றும் படிகட்டுகளில் இருக்கும்
ஆனால் அவை விசாரிக்க ஏதுவாக இல்லை!
Macavity அங்கு இல்லை!
இழப்பு வெளிப்படுத்தபட்டதால்;
ரகசிய சேவை கூறியது. இது Macavity தான்!” ஆனால் பல மைல்கள் தள்ளி இருப்பான்.

கண்டிப்பாக அவன் ஓய்வெடுக்கும் போது
அவன் கட்டைவிரலை நக்குவான்
அவன் தீவிரமாக பல கடினமான பெரிய செயல்களைச் செய்வான்.
Macavity, Macavity அவன் போல் யாரும் இல்லை
நம்பிக்கையும் (suavity) தந்திரமும் (deceitfulness) கொண்ட பூனையை பார்த்ததில்லை.

அவன் எப்போதும் வேற்றிட வாதம் கொண்டவன்,
ஒன்று அல்லது இரண்டு இடங்கள் தவிர
எந்த நேரத்தில் சில செயல்கள் ஏற்பட்டால்,
Macavity அங்கு இருப்பதில்லை!
அனைத்து பூனைகளின் சிறந்த செயல்கள்
அறிதாய் இருக்கும் என அவர்கள் கூறுவார்கள்.
(Mungojerrie பற்றி கூறுகிறேன், Griddlebone பற்றி கூறுகிறேன்)
அனைத்து நேரமும் முகவர்கள் போல் சிறந்தவர்கள் இல்லை
இதைப் போன்று இயக்கத்தை தடுக்க; நெப்போலியனின் குற்றங்கள்.
ஆகையால் Macavity யை Napoleon of crime என்று கூறினர்.

Tamilnadu State Board New Syllabus Samacheer Kalvi 12th Bio Botany Guide Pdf Chapter 9 Plant Breeding Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 12th Bio Botany Solutions Chapter 9 Plant Breeding

12th Bio Botany Guide Plant Breeding Text Book Back Questions and Answers

I. Choose the correct answer

Question 1.
Assertion : Genetic variation provides the raw material for selection.
Reason : Genetic variations are differences in genotypes of the individuals.
a) Assertion is right and reason is wrong.
b) Assertion is wrong and reason is right.
c) Both reason and assertion is right.
d) Both reason and assertion is wrong.
Answer:
b) Assertion is wrong and reason is right.

Question 2.
While studying the history of domestication of various cultivated plants ………………. were recognized earlier.
a) Centres of origin
b) Centres of domestication
c) Centres of hybrid
d) Centres of variation
Answer:
a) Centres of origin

Question 3.
Pick out the odd pair …………..
a) Mass selection – Morphological characters
b) Purline selection – Repeated self pollination
c) Clonal selection — Sexually propagated
d) Natural selection – Involves nature
Answer:
c) Clonal selection – Sexually propagated

Question 4.
Match Column I with Column II

Answer:
b) i -III, ii-I, iii-IV, iv-II

Question 5.
The quickest method of plant breeding is
a) Introduction
b) Selection
c) Hybridization
d) Mutation breeding
Answer:
b) Selection

Question 6.
Desired improved variety of economically useful crops are raised by
a) Natural selection
b) hybridization
c) mutation
d) biofertilisers
Answer:
b) hybridization

Question 7.
Plants having similar genotypes produced by plant breeding are called
a) clone
b) haploid
c) autopolyploid
d) genome
Answer:
a) clone

Question 8.
Importing better varieties and plants from outside and acclimatising them to local environment is called
a) cloning
b) heterosis
c) selection
d) introduction
Answer:
d) Introduction

Question 9.
Dwarfing gene of wheat is
a) pal 1
b) Atomita 1
c) Norin 10
d) pelita 2
Answer:
c) Norin 10

Question 10.
Crosses between the plants of the same variety are called
a) interspecific
b) inter varietal
c) intra varietal
d) inter generic
Answer:
c) Intra varietal

Question 11.
Progeny obtained as a result of repeat self pollination a cross pollinated crop to called
a) pure line
b) pedigree line
c) inbreed line
d) heterosis
Answer:
b) Pure line

Question 12.
Jaya and Ratna are the semi dwarf varieties of
a) wheat
b) rice
c) cowpea
d) mustard
Answer:
b) Rice

Question 13.
Which one of the following are the species that are crossed to give sugarcane varieties with high sugar, high yield, thick stems and ability to grow in the sugarcane belt of North India?
a) Saccharum robustum and Saccharum officinarum
b) Saccharum barberi and Saccharum officinarum
c) Saccharum sinense and Saccharum officinarum
d) Saccharum barberi and Saccharum robustum
Answer:
b)Saccharum barberi and Saccharum officinarum

Question 14.
Match column I (crop) with column II (Corresponding disease resistant variety) and select the correct option from the given codes.

Answer:
b) I-(ii), II-(i), IH-(iii), IV-(iv)

Question 15.
A Wheat variety, Atlas 66 which has been used as a donor for improving cultivated wheat, which is rich in
a) iron
b) carbohydrates
c) proteins
d) vitamins
Answer:
c) proteins

Question 16.
Which one of the following crop varieties correct matches with its resistance to a disease

Answer:
a) Pusa Komal – Bacterial blight

Question 17.
Which of the following is incorrectly paired?
a) Wheat – Himgiri
b) Milch breed – Sahiwal
c) Rice – Ratna
d) Pusa Komal – Brassica
Answer:
d) Pusa Komal – Brassica

Question 18.
Match list I with list II

a. i c, ii a, iii b, iv d
b. i d, ii c, iii a, iv b
c. i a, ii c, iii b, iv d,
d. i b, ii a, iii d, iv c
Answer:
b. i d, ii c, iii a, iv b

Question 19.
Differentiate primary introduction from secondary introduction
Answer:

Question 20.
How are microbial innoculants used to increase the soil fertility?
Answer:

Biofertilizers or microbial innoculants are defined as preparations containing living cells or latent cells of efficient strains of microorganisms that help crop plants uptake of nutrients by their interactions in the rhizosphere when applied through seed or soil.

They are efficient in fixing nitrogen, solubilising phosphate and decomposing cellulose. They are designed to improve the soil fertility, plant growth, and also the number and biological activity of beneficial microorganisms in the soil. They are ecofriendly organic agro inputs and are more efficient and cost effective than chemical fertilizers.

Question 21.
What are the different types of hybridization?
Answer:
Types of hybridization:

(i) Intravarietal hybridization:
The cross between the plants of same variety. such crosses are useful only in the self. pollinated crops.

(ii) Intervarietal hybridization:
The cross between the plants belonging to two different varieties of the same species and is also known as intraspecific hybridization.

(iii) Interspecific hybridization:
The cross between the plants belonging to different species belonging to the same genus is also called intragenic hybridization.
Example:
Gossypium hirsutum
Gossypium arboreum

(v) Intergeneric hybridization:

• The crosses are made between the plants belonging to two different genera.
• The disadvantages are hybrid sterility time consuming and expensive procedure.
  Example : Raphanobrassica x Triticale

Question 22.
Explain the best suited type followed by plant breeders at present?
Answer:
Mutation breeding represents a new method of conventional breeding procedures as they have the advantage of improving the defect without losing an agronomic and quality character in agriculture and crop improvement. Mutation means the sudden heritable changes in the genotype or phenotype of an organism. Gene mutations are of considerable importance in plant breeding as they provide essential inputs for evolution as well as for recombination and selection. It is the only method for improving seedless crops.

Question 23.
Write a note on heterosis.
Answer:

• The superiority of the FI hybrid in performance over its parents is called heterosis or hybird vigour.
• G.H. Shull was the first scientist to use the term heterosis in 1912.
• Heterosis are of the following types.
• Euheterosis, Mutational Euheterosis, Balanced Euheterosis and Pseudoheterosis

(i) Euheterosis:
This is the true heterrosis which is inherited and is further classified as.

(a) Mutational Euheteosis:
Simplest type of euheterosis and results from the sheltering or eliminating of the deleterious unfavourable often lethal, recessive, mutant genes by their adaptively superior dominant alleles in cross pollinated crops.

(b) Balanced Euheterosis :
well balanced gene combinations which is more adaptive to environmental conditions and agricultural usefulness.

(ii) Psuedohetrosis:
Also termed as luxuriance progeny possess superiority over parents in vegetative growth but not in yield and adaptation usually sterile or poorly fertile.

Question 24.
List out the new breeding techniques involved in developing new traits in plant breeding.
Answer:
New Breeding Techniques (NBT) are a collection of methods that could increase and accelerate the development of new traits in plant breeding. These techniques often involve genome editing, to modify DNA at specific locations within the plants to produce new traits in crop plants. The various methods of achieving these changes in traits include the following.

• Cutting and modifying the genome during the repair process by tools like CRISPR /Cas.
• Genome editing to introduce changes in a few base pairs using a technique called Oligonucleotide-directed mutagenesis (ODM).
• Transferring a gene from an identical or closely related species (cisgenesis).
• Organizing processes that alter gene activity without altering the DNA itself (epigenetic methods)

12th Bio Botany Guide Plant Breeding Additional Important Questions and Answers

I. Match the Following

Question 1.

A) a – iv, b – iii, c – ii, d – i
B) a – iv, b – ii, c – iii, d – i
C) a – ii, b – i, c – iv, d – iii
D) a – i, b – iv, c – ii, d – iii
Answer:
A) a – iv, b – iii, c – ii, d – i

Question 2.

A) a – ii, b – iii, c-iv, d-i
B) a – iii, b-ii, c-i, d-iv
c) a – iii, b – i, c-ii, d-iv
D) a – i, b-iv c-iii, d-ii
Answer:
c) a – iii, b – i, c – i, d – iv

Question 3.

A) a – ii, b – iii, c- i, d – iv
B) a – i, b – ii, c – iv, d – iii
c) a – iv, b – i, c – ii, d – iii
D) a – iii, b – iv c – i, d – iv
Answer:
D) a – iii, b – iv c – i, d – iv

Question 4.

A) a – i, b – ii, c – iv, d – iii
B) a – ii, b – iii, c – iv, d – i
c) a – iii, b – iv, c – i, d – iii
D) a – iv, b – i, c – iii, d – ii
Answer:
B) a – ii, b – iii, c – iv, d – i

II. Choose the Odd man Out

Question 1.
a) Rhizoblum
b) Azolla
c) Trichoderma
d) Arbuscular mycorhizae
Answer:
c) Trichoderma

Question 2.
a) Anabaena
b) Amanita
c) Nostoc
d) Azospirillum
Answer:
b) Amanita

Question 3.
a) Natural selection
b) Mass selection
c) Purelinc selection
d) Clonal selection
Answer:
a) Natural selection

Question 4.
a) Cesium
b) Nitromethyl
c) Urea
d) X-ray
Answer:
d) X-ray

III. Choose the incorrect Pair

Question 1.

Answer:
d) South America – Onion

Question 2.

Answer:
C) Dr. K. Ramiah – Wheat breeder

Question 3.

Answer:
a) N2 Fixing Bacteria – Bacillus

Question 4.

Answer:
c) Green Manuring – Sonora – 63

IV. Choose the incorrect Pair

Question 5.

Answer:
b) Blast resistant Rice -1940

Question 6.

Answer:
a) Green Manuring – Tephrosia purpurea

Question 7

Answer:
c) M.S. Swaminathan – TN 1 – hybrid rice

Question 8.

Answer:
d) Cauliflower – Pusa shubhra

V. Assertion and Reason

Question 1.
Assertion : Growing of green manure crops and use of these crops as manure is called Green Manuring.
Reason : It helps to increase the nitrogen in the soil.
a) A & R are true.
b) A & R are Wrong.
c) A is true and R is Wrong.
d) A is wrong and R is true.
Answer:
a) A & R are true.

Question 2.
Assertion : Dr. M.S. Swaminathan is called “Father of green revolution in India.
Reason : He strived hard for conservation of traditional rice varities.
a) Both A & R is True.
b) Both A & R is Wrong.
c) A is True and R is Wrong.
d) A is wrong and R is True.
Answer:
c) A is True and R is Wrong

Question 3.
Assertion(A): A variety formed by pure line selection method shows more homozggosity with respect to all genes.
Reason(R): The pure line plants are produced by asexual method of vegetative propagation method.
a) (A) is correct; (R) is wrong
b) (A) is wrong; (R) is correct
c) (A) is correct; (R) does not explain
d) (A) is correct; (R) explain (A)
Answer:
a) (A) is correct; (R) is wrong

Question 4.
Assertion : Earliest record of Agriculture is found in the fertile Crescent region in and around River Nile
Reason : Approximately 12000, years ago Fertile crescent region is in and around. Tigris and Euphrates river.
a) Both A & R are True.
b) Both A & R are Wrong.
c) A is True and R is Wrong.
d) A is Wrong and R is True.
Answer:
d) A is Wrong and R is True

VI. Choose the Correct Statements

Question 1.
a) Vavilov Studied 247 Cultivated plants
b) Zhukovsky divided the whole world into 12 mega gene centres.
c) Valvilo intially propose 12 main geographic centres of origin
d) Harlan put forward the concept of mega gene centre for the origin of cultivated plants
Answer:
b) Zhukovsky divided the whole world into 12 mega gene centres

Question 2.
a) Foxtail mullet was domesticated by India
b) Wheat & Pea war domesticated by Ethiopia.
c) Castor and Coffee was domesticated by central East
d) Tomato & Pineapple was domesticated by south America
Answer:
d) Tomato & Pineapple was domesticated by south America

Question 3.
a) Seaweeds has more than 70 minerals vitamins and enzymes
b) Trichoderma is a parasitic fungi.
c) Rhizobium is a pathogenic bacteria
d) Azolla is submerged water fern
Answer:
a) Seaweeds has more than 70 minerals vitamins and enzymes

Question 4.
a) Hirngiri is a wheat variety that is resistant to Bacterial blight disease.
b) A Variety of CowPea, Pusakomal is resistent to Hill bunt disease.
c) Pusa shubra is a cauliflower variety that is resistant to Black rot disease
d) Pusa swarnim is a variety of Brassica that is resistent to TMV disease
Answer:
c) Pusa shubra is a cauliflower variety that is resistant to Black disease

VII. Choose the incorrect Statements

Question 1.
a) Mr. Jayaraman was a disciple of Dr. Nammalvar
b) Normal E. Borlaug was awarded Noble prize for peace in 1970.
c) M.S. Swaminathan produced the first semidwarf fertiliser responsive hybrid variety of rice TN 1..
d) Green revolution the term was Coined by Muller
Answer:
d) Green revolution the term was Coined by Muller

Question 2.
The disadvantage of pureline selection is
a) It is difficult to distinguish between hereditary variation from environmental variation.
b) New genotypes are never created so they are less stable to environmental fluctuations
c) The genotype is unchanged for a long period of time.
d) The plants show more heterozygosity.
Answer:
c) The genotype is unchanged for a long period of time.

Question 3.
The possible changes in the plant species due to domestication are
a) Adaptation to a greater diversity of environments.
b) Uniform flowering and fruiting.
c) Drop in Yield
d) Change in breeding system
Answer:
c) Drop in yield

Question 4.
a) Rhizobiurn is best suited for the wheat fields.
b) Azolla that fixes the atmospheric nitrogen along with blue green algae.
c) Arbuscular mycorrhizae also assures water availability
cl) Sea weed liquid fertilizer improves resistance of plants to frost and disease.
Answer:
a) Rhizobium is best suited for the wheat fields

VIII. Choose the correct answer.

Question 1.
The domesticated crop of Mesoamerica is …………………..
a) Tomato
b) Pine apple
c) Sweet Potato
d) Rubber
Answer:
a) Tomato

Question 2.
The domesticated plant of the chiloe centre.
a) Maize
b)Potato
c) Tobacco
d) Olive
Answer:
a) Maize

Question 3.
The domesticated plant of the Near East is______
a) Rye
b) Rice
c) hemp
d) Cotton
Answer:
a) Rye

Question 4.
Name the rice variety with saline tolerance and pest resistance.
a) Wild-type rice
b) Atomita – 2
c) Dwarf rice variety
d) Golden rice
Answer:
b) Atomita -2

Question 5.
Biofertilizers could be also called as …………………
a) Viral inoculants
b) Myco inoculants
c) Protozoan inoculants
d) Bacterial Inoculants
Answer:
d) Bacterial Inoculants

Question 6.
Beauveria species act as a parasite on …………… species.
a) Mammals
b) Aves
c) Arthropod
d) Amphibians
Answer:
c) Arthropod

Question 7.
Damping off of ……………. is caused by Rhizoctonia solani.
a) Tomato
b) Potato
c) Millet
d) Maize
Answer:
a) Tomato

Question 8.
Pongamia pinnata is an important plant species useful for ………………. manure.
a) Organic
b) Potassium rich
c) Green leaf
d) Calcium rich
Answer:
c) Green leaf

Question 9.
Match the following and find the correct answer
(i) Rhizobium – (A) Water ferm
(ii) Trichoderma – (B) Green manuring
(iii) Azolla – (C) Symbiotic bacterium
(iv) Crotolaria – (D) Free living fungus
a) (i) B; (ii) C; (iii) D; (iv) A
b) (i) C; (ii) D; (iii) B; (iv) A
c) (i) C; (ii) D; (iii) A; (iv) B
d) (i) B; (ii) D; (iii) C; (iv) A
Answer:
c) (i) C; (ii) D; (iii) A; (iv) B

Question 10.
More Vigorous hybrid corn was developed in _______
a) 1926
b) 1943
c) 1950
d) 1936
Answer:
a) 1926

Question 11.
In 10,000 BC Domestication of ……………….. was done.
a) Maize
b) Paddy
c) Wheat
d) Sugar cane
Answer:
c) Wheat

Question 12.
The newly introduced plant was carefully examined by the process called …………….
a) PCR Method
b) Dots Method
c) Cisgenesid
d) Quarantine
Answer:
d) Quarantine

Question 13.
National Bureau of plant Genetic Resources is located at ……………….
a) Rangpuri
b) Andhra
c) Pune
d) Bihar
Answer:
a) Rangpuri

Question 14.
Hereditary Variation cannot be distinguished from environmental variation in ………………
a) Pureline selection
b) Clonal Selection
c) Mass Selection
d) Hybridization
Answer:
c) Mass Selection

Question 15.
Johannsen in 1903 coined the word.
a) Clonal Selection
b) Pure line
c) Mass Selection
d) Heterosis
Answer:
b) Pure line

Question 16.
Which one of the following is a biopesticide?
a) Azolla
b) Rhizobium
c) Beauveria
d) Hevea
Answer:
c) Beauveria

Question 17.
…………….. is the best suited measure for maintaining hybrid vigour.
a) Asexual reproduction
b) Vegetative Propagation
c) Grafting
d) Cutting
Answer:
b) Vegetative Propagation

Question 18.
…………. is also termed as luxuriance.
a) Euheterosis
b) Heterosis
c) Mutational heterosis
d) Pseudo heterosis
Answer:
d) Pseudo heterosis

Question 19.
Muller and Stadler coined the term ………………….
a) Mutation Breeding
b) Modern Breeding
c) Plant Breeding
d) Poly ploidy
Answer:
a) Mutation Breeding

Question 20.
Mutation Breeding is the only method of improving …………… crops.
a) Multi seeded
b) single seeded
C) seedless
d) Nutritional
Answer:
c) seedless

Question 21.
Bose Research institute at Calcutta is the first …………. in India.
a) Botanical garden
b) planatorium
c) Zoological park
d) Gamma garden
Answer:
d) Gamma garden

Question 22.
Which one of the following selection method takes longer time in bringing about desired variation?
a) clonal selection
b) Mass selection
c) pureline selection
d) Natural selection
Answer:
d) Natural selection

Question 23.
(A) was originally grown in North India
(B) was orginally grown in South India
a) (A) Saccharum officinarum (B) Saccharum bareri
b) (A) Saccharu bareri (B) Saccharum officinarum
c) (A) Saccharum coarctatum (B) Saccharum alopecuroidum
d) (A) Saccharum alopecuroidum (B) Saccharu coarctatum
Answer:
b) (A) Saccharu bareri (B) Saccharum officinarum

Question 24.
Green revolution is the ………………. Agricultural revolution.
a) Third
b) second
c) third
d) fourth
Answer:
a) Third

Question 25.
…………….. received the national award for best genome saviour. .
a) Nel jeyaraman
b) C.T.Patel
c) Dr.B.P.Pal
d) N.G.P.Rao
Answer:
a) Nel jeyaraman

Question 26.
……………. is the breeding of crops for improved nutritional quality
a) Plant Breeding
b) Heterosis
c) Mutation
d) Biofortification
Answer:
d) Biofortification

Question 27.
High aspartic acid maize leads to resistance to ………………….
a) aphids
b) jassids
c) maize stem borer
d) leaf roller
Answer:
c) maize stem borer

Question 28.
Which one of the following is not a free living N2 fixing organism?
a) Anabaena azollae
b)Azotobacter
c) Clostridium
d) Nostoc
Answer:
c) Clostridium

IX. Fill in the blanks.

1. De candolle in his ……………. studied 247 caltivated plants.
Answer:
Origen of cultivated plants

2. Bamboo eas demesticated by ……………….
Answer:
China

3. He was an eminet Sorghum breeder,devoloped World’s first hybrid of Sorghum CSH-1.
Answer:
N.G.P.Rao.

4. ……………… is used as a biofertilizer for wetland rice cultivation
Answer:
Azolla.

5. Vavilov in the year ………………. converted 8 main geographic centres of origin to 12
Answer:
1935

6. Harlan says that the centre of crop plants means the places of ……………… origin of the crop plants.
Answer:
Agricultural

7. The ……………… was domesticate only in the Chiloe centre
Answer:
Potato

8. ………………. could be also called as Bioinoculants
Answer:
Biofertilizers

9. C.T.Patel devoloped World’s first …………….. hybrid
Answer:
Cotton

10. Choudhary ram dhan made …………….. as punjab granary of India.
Answer:
Wheat

11. Azdla is used as biofertiliser for wetland rice cultivation and is known to contribute ……………./ha/crop.
Answer:
40-60 kg

12. …………….. is Associated with Phycomycetous fungi and angiosperm roots.
Answer:
Arbuscular Mycorhizzoe

13. ……………… contains Auxin,Cytokinin and Gibberellins
Answer:
Seaweed liquid fertiliser

14. ……………… species are free living fungi that are common in soil and root ecosystem
Answer:
Trichoderma

15. Damping of tomato is caused by ……………..
Answer:
Rhizoctonia Solani

16. It is one of the most important green manure crops
Answer:
Tephrosia Purpurea

17. The double helix structure of DNA was identified by ……………. and …………….
Answer:
James Watson,Francis Crick

18. By 2050 we will …………….. need more food to feed the rapid growing population.
Answer:
50%

19. Crop domestication started early during ……………….
Answer:
10,000 Bc

20. ………………. Corn was developed using targetted breeding.
Answer:
Waxy

21. Rice variety of ……………. introduced from Philippines
Answer:
IR8

22. NBPGR is located in Chennai at …………………..
Answer:
Meenembakkan

23. Introduced plants get adapted to the new environment is called as ……………….
Answer:
Acclimatization

24. Tea varieties collected from China and North East India initially grown in Botanical garden of ……………….
Answer:
Kolkatta
Selection

25. ______ is the oldest and basic method of plant breeding
Answer:
Preliminary

26. In clonal selection …………… yield trial takes place during 3rd year.
Answer:
Intrageneric

27. Interspecific hybridization is also called as _____
Answer:
hybridization

28. Green revolution scheme began in ……………. in 1940’s.
Answer:
Mexico

29. In 2005 …………….. organized a first ever traditional paddy seed festival in his farm as an individual.
Answer:
Nel jayaraman

30. …………… is a cleaving protein.
Answer:
Cas9

X. Two Marks

Question 1.
What is Economic Botany?
Answer:
It is the study of the relationship between people and economically important plants.

Question 2.
When did people started practising Agriculture?
Answer:

• Archeological evidence for earliest record of agriculture is found in the fertile crescent region in and around Tigris and Euphrates river valleys, approximate about 12,000 years
  ago

Question 3.
What was the contribution by De Candolle towards agriculture?
Answer:

• He studied 247 cultivated plant species.
• He attempted to solve the mystery about the anscestral form, region of domestication and history.

Question 4.
How many geographic centres were proposed by vavilov?
Answer:

• Initially he proposed eight main geographic centres of origin.
• Later by dividing few centres into two or three centres and added a new centre USA.
• Thus making the 8 centres of Origin into 12.

Question 5.
Define Biofertilizers.
Answer:

• It is defined as preparations containing living cells of efficient strains of micro organisms that help in crop yield.

Question 6.
What is component of seaweed liquid fertilizer?
Answer:

• It contains Cytokinin, Gibberellins, and auxin a part from macro & micro nutrients.
• It has Alginates, Carbohydrate, 70 types of minerals, Vitaming and enzymes.

Question 7.
Trichoderma has been recognised as bio¬control agent – Give Reasons.
Answer:

• It control plant diseases
• Ability to enhance root growth.
• Increases crop productivity.
• Provides resistance to abiotic stress.
• Helps in uptake and use of nutrients.

Question 8.
What is plant introduction?
Answer:

• Introduction of genotypes from a place where it is normally grown to a new place.
• eg. IR & Rice from Philippines.

Question 9.
Define Acclimatization?
Answer:

• The adjustment or adaptation of the introduced plant in the changed environment is called acclimatization.

Question 10.
What is Quarantine?
Answer:

• All the introduced Crop must be free from presence of weeds, insects and disease causing Organisms.
• It has to be carefully examined by the process called quarantine.
• A strict isolation imposed to prevent the spread of disease.

Question 11.
What is Natural Selection?
Answer:

• This is a rule in the nature.
• It results in evolution reflected in the Darwinian’s principle survival of the fittest.
• It takes longer time to bring about desired Variation.

Question 12.
What is Arificial Selection?
Answer:

• It is a human involved process.
• Having better crop from a mixed population.
• The individuals differ in character.

Question 13.
Name the three types of Artificial Selection.
Answer:
a) Mass Selection,
b) Pureline Selection,
c) Clonal Selection

Question 14.
What is Emasculation
Answer:

• It is a process of removal of anthers to prevent self pollination before the opening of a flower.

Question 15.
What are the various types of Mutagens?
Answer:

• Physical Mutagen – UV short wave, X-ray, Alpha, Beta and Gamma Waves.
• Chemical Mutagen – Cesium, Ethylmethane sulfonate Nitromethyl and Urea.

Question 16.
What is Gamma Garden?
Answer:

• It is a form of mutation breeding.
• The Radioactive sources are cobalt – 60 and Caesium -137
• The first Gamma Garden in India is Bose Research institute at Calcutta.

Question 17.
What are the benefits of polyploidy?
Answer:

• It often exhibit increase hybrid vigour.
• Increase the tolerance to both biotic and abiotic stresses

Question 18.
How Polyploidy can be induced? List out the products achieved through polyploidy.
Answer:

• Polyploidy can be induced by the use of cochicine to double the chromosome number.
• Seedless Tomato, Apple, Watermelon and orange.

Question 19.
Define Green Revolution.
Answer:

• It is the cumulative result of a series of research, development, innovation and technology transfer initiatives in Agriculture.

Question 20.
Write about the contribution of Dr. M.S.Swaminathan in mutation breeding.
Answer:

• He is the pioneer mutation breeder.
• He has produce sharbati Sonora is the amber grain coloured variety of wheat.
• He is responsible for green revolution in India.

Question 21.
What are the objectives considered in Breeding to improve the nutritional quality of plants?
Answer:
To improve protein, oil, vitamin, Micronutrient and mineral content and quality

Question 22.
Tabulate certain crops and the pest resistant Variety?
Answer:

Question 23.
Expand the following.
Answer:

• CRISPR – Clustered Regularly Interspaced short Palindromic Repeats
• ODM – Oligonucleotide – Directed Mutagenesis.

Question 24.
Which method of artificial vegetative reproduction is good in plants. Give reason for your answer.
Answer:
Tissue culture is the modern artifical reproductive technique.

Reasons:

•  large scale production of clones (genitically uniform population) from the callus tissue – developed from the chosen explant cells (invitro)
• Both crop and tree species useful in forestry can be produced with desirable characters in large numbers with in a short span of time.

Question 25.
What are the advantages of rice field?
Answer:

• Azolla is a free floating water fern that fixes atmospheric nitrogen in association with nitrogen fixing blue green algae. Anabaena azolla.
• It is used as a bio-fertilizer for wetland rice cultivation and is known to contribute 40-60 kh/hal/crop.

Question 26.
Write the any three names of plant species useful in green manure?
Answer:

• Cassia fistula
• Sesbania grandiflora
• Azadirachta indica

Question 27.
What is Bio-pesticides with example
Answer:
Bio-pesticides are biologically based agents used for the control of plant pests.
Example: Trichoderma.

XI. Differentiate Type Questions

Question 1.
Differentiate Biofertilizers and Green manuring
Answer:

Question 2.
Differentiate Pureline selection and clonal selection
Answer:

Question 3.
Differentiate Mutation Breeding and Polyploid Breeding
Answer:

Question 4.
Differentiate Intervarietal and Interspecific Hybridization.
Answer:

XII. Three marks

Question 1.
What are the fields involved in Economic Botany?
Answer:

• Agronomy, Anthropology, Archaeology, Chemistry, trade and commerce.

Question 2.
Define Domestication.
Answer:

• It is the process of bringing a plant species under the control of humans and gradually changing it through careful selection.

Question 3.
What is Organic Agriculture?
Answer:

• It is as alternative agricultural system.
• It is due to rapidly changing farming practices.
• It is a production system that sustains the health of the soils, ecosystems and people.
• It is based on ecological processes biodiversity and cycles adapted to local conditions

Question 4.
Write about the role played by Beauveria as a Bio-pesticide
Answer:

• It is an entomo-pathogenic fungi
• It acts as a parasite on various arthropod that causes white muscardine disease.
• It also controls datnping off of tomato caused by Rhizoctonia Solani.

Question 5.
Differentiate Green manuring and Green leaf manuring.
Green Manuring

• Growing of green manure crops and use these crops directly in the field by ploughing.
• It increases the nitrogen in the soil.
• It helps to improve the physical property of the soil.
  eg. Crotalaria juncea.

Green Leaf Manuring

• Application of green leaves twigs, shrubs, plants growing in wasteland and field bunds.
• The important plant species useful for green leaf manure are – cassia fistula. Delonix regia.

Question 6.
Define plant breeding
Answer:

• Plant breeding is the science of improvement of crop varities with higher yield better quality, resistance to diseases and shorter durations which are suitable to particular environment.

Question 7.
What is the plan of thrid Agricultural Revolution
Answer:
The Green revolution or thrid Agricultural Revolution is the intensive plan of 1960’s to increase crop yield in developing countries by introducing the high yielding, resistant varieties, increased irrigation facilities, fertilizer application and better agricultural management.

Question 8.
Draw a flow chart showing the steps involved in plant Breeding.
Answer:
The main steps in plant breeding are given below

Question 9.
Write about NBPG R
Answer:

• It is responsible for introduction and maintence of germplasm of various agricultural and horticultural station in our country.
• It is also responsible for maintenance of plant materials of botanical and medicinal interest.
• It is located at Rangpuri/New Delhi with four regional station at Amristar, Kolkata, Mumbai and Chennai.

Question 10.
Draw the Schematic difference between Mass & Pureline selection.
Answer:

Question 11.
What is hybridization?
Answer:

• Hybridization is the method of producing new crop verities by crossing of plants that are genetically different.
• It offers improvement in crop by combining the desirable character of two or more varities.
• The first natural hybridization was observed by Cotton Mather in maize.

Question 12.
A type of Heterosis is called as Pseudoheterosis – Why?
Answer:

• It is called as pseudoheterosis because the progeny is superior over parents by vegetative growth.
• They are usually sterile.
• It is also called as Luxuriance.

Question 13.
Tabulate certain crop variety and the disease to which they are resistant.
Answer:

Question 14.
What is Norm 10?

• It is dwarfing genes with high photosynthetic rate and increases the respiratory activity.
• Gonjiro Inazuka was scientist, who selected the Semi- dwarf wheat variety – Norm 1o.
• This variety helped one billion lives from hunger and starvation.

Question 15.
How can we develop resistance to Insect pests in plants?

• Insect resistance in host crop plants may be due to morphological, biochemical 0r physiological characteristics.
• Hairy leaves in plants – Jassids in cotton
  – Cereal leaf bettle in wheat.
• Solids Stem – Stem sawfly.
  Smooth leaves and nectar less cotton – Bol worms.
  High aspartic acid, low nitrogen and sugar content – Maize stem borers.

Question 16.
What are the plant breeding tools used to improve the crop varieties?
Answer:

• Genetic Engineering, plant tissue culture, protoplasmic fusion, Molecular marking and DNA finger printing.

Question 17.
Define mutation breeding?
Answer:
Mutation means the sudden heritable changes in the genotype or phenotype of an organism.

Question 18.
What is Bio-fortification?
Answer:
Breeding crops with higher levels of vitamins and minerals or higher protein and healthier fats is the most practical means to improve public health.

Question 19.
Comment on sugercane.
Answer:

• Saccharum bareri was originally grown in north India.
• It is poor sugar content and yield.
• Tropical canes grown in south India saccharurn officinarum had thicker stems and higher sugar content.
• It did not grow well in North India
• These two species were successfully crossed to get sugar cane varieties combining the desirable qualities of high yield thick stems high sugar and ability to grows in the sugar cane areas of North India.

XIII. Five Marks

Question 1.
What are the possible changes in the plant due to domestication?
Answer:

• Adaption to the environmental alteration.
• Adaption to wider geographical range.
• Uniformity in flowering and fruiting.
• Increased size of fruits and seeds.
• Change in breeding system.
• Increase in yield.
• Increased resistance for disease and pest.
• Developing seedless parthenocarpic fruit.
• Enhancing the taste and nutritional composition.

Question 2.
Enumerate the History of Agriculture:
Answer:

• 1807 – Alexander Yon Humboldt considered that original & source of most and their origin is an importable secret.
• 1868 – Darwin’s theory proposed that natural selection and hybridization led to the origin of cultivate plants.
• 1883 – De Candolle studied 247 cultivated plants species and was able to find the ancestral form, region of domestication and history.
• 1887-1943 – Vavilov studied about the diverse forms of plants based on various criteria like morphology,cytology etc., He proposed 8 geographic centres and later developed it to 12 centres.
• 1968 – Zhukovsky put forward the concept of mega gene and divided the whole world into 12 mega gene centres.
• 1971 – Harlen believed that agriculture originated independently in three different areas.
  – There were non centres are the area were the crop has been shifted.

Question 3.
Tabulate the vavilov’s centres of crop origin and crop domesticated.
Answer:
Vavilov’s centres of crop origin and crops domesticated.

Question 4.
Write an essay on Indian plant Breeders.
Answer:

• Dr.M.S.Swaminathan- He is pioneer in mutation breeder.
• Sir.T.S.Venkatraman- An eminent sugarcane breeder.
• Dr.B.P.Pal-Developed superior disease resistant varieties of wheat
• Dr.K.Ramiah- Eminent Rice Breeder.
  N.G.P.Rao-An eminent sorghum breeder, developed world’s first hybrid of sorghum (CSH-1).
• C.T.Patel-Developed world’s first cotton hybrid.
• Choudhary Ram Dhan – wheat breeder,developed C-591 wheat which made Punjab as wheat granary of india.

Question 5.
Differentiate Rhizobium from Azolla as bio-fertilizers.
Answer:

• Bio-fertilizers could also be called as microbial cultures or bacteria) fertilizers.
• They are efficient in fixing nitrogen improve soil fertility, eco-friendly and cost effective.

Rhizobium:

• It resides in the root nodules of leguminous plants.
• It fixes the atmospheric Nitrogen.
• It increases yield of paddy by 15-40%

Azolla:

• Free floating water fern, with blue green algae fixes the Nitrogrn.
• It increases the yield of rice.
• It decomposes quickly.

Arbuscular Mycorrhizae:

• They can dissolve the phosphates found in the soil.
• It provides strength to resist disease, germ and unfavourable weather.

Seaweed Liquid Fertilizer:

• It contains cytokinin, gibberellins and Auxin
• Most of it are made from kelp ( Brown Algae).
• The alginates in it react with metals in soil and retain moisture for a long time.
• They have more than 70 minerals vitamin and enzymes.
• Seeds soaked in seaweed germinate rapidly.

Question 6.
Tabulate the classification of Biofertilizers.
Answer:

Question 7.
Discuss about Biopesticides in detail.
Answer:

• They are biologically based agents used for the control of plant pests.
• They are ecofriendly , Non – toxic and cheaper the chemical pesticide.

Trichoderma:

• They are free living fungi in the soil.
• They control plant disease.
• It has the ability to enhance root growth development.
• Increases the crop productivity.
• It helps in resisting Abiotic stress.
• It increases the uptake and use of nutrients.

Beauveria:

• It is an entomo – pathogenic fungus
• It parasitse arthropods that cause white muscardine and controls damping off of tomato

Question 8.
Enumerate the objectives of plant Breeding.
Answer:

• To increase yield, Vigour and fertility of the crop.
• To increase tolerance to environmental condition, Salinity, Temperature and drought.
• To prevent premature falling of buds fruits etc.,
• To improve the maturation of both the male and female gametes at the same time.
• To develop resistance to pathogens and pests.
• To develop photosensitive and thermos – Sensitive Varieties.

Question 9.
Discuss about the types of selection.
Answer:

• Selection is the oldest and basic method of plant breeding.
• There are two main types of selection – Natural and Artificial.

Natural Selection:

• It occurs naturally.
• It takes longer time in bringing about desired variation.
• It reflected the Darwinian principle.

Artificial Selection:

• It is a human involved process.
• Producing better crop from a mixed population.

a) Mass Selection :

• Large number of plants of similar phenotype are selected and crossed to get a new variety.
• After repeated selection for five to six years it is distributed to the farmers.

b) Pureline Selection:

• Plants obtained as a result of self pollination from a single homozygous individual.
• The progeny shows homozy gosity with respect to all genes.
• New Genotypes are never created,

c) Clonal Seection:

• The progenies that are asexually propagated resembles the parent genetically.
• The progeny is multiplied to form clone.
• The genotype of a clone remains unchanged for a long period of time.

Question 10.
Describe the steps involved in Hybri-dization.
Answer:
a) Selection of Parents :

• Male and female plants of desired characters are selected.
• It should be tested for their homozygosity

b) Emasculation:

• It is removal of anther before blooming.
• It avoids self pollination

c) Bagging:
The stigma is protected against any undesirable pollen grains, by covering with a bag.

d) Crossing:
Transfer of pollen grains from selected male flower to the stigma of the emasculated female flower.

e) Harvesting Seeds and Raising Plants :

• Due to fertilization seeds form.
• These seeds are grown into a new generation.

Question 11.
Discuss about the types of heterosis.
Answer:
a) Euheterosis:

• It is the true heterosis.
• It is inherited

b) Mutational Euheterosis :

• It is the simplest form.
• Removal of harmful, recessive, mutant genes by superior dominant allele in cross pollinated crops.

c) Balanced Euheterosis:

• Well balanced gene combination.
• More adaptive to environment and agricultural usefulness.

d) Psuedo heterosis :

• Also known as luxuriance.
• Progeny possess superiority over parents in regetative Growth.
• But not in yield & adaptation.
• Usually sterile or poorly fertile.

Question 12.
Describe polyploid Breeding.
Answer:

• The plants which posses more than two sets of chromosomes are called Polyploids.
• It is the major force in the evolution of both wild and cultivated plants.
• Polyploid of exhibit hybrid vigour.
• Increases tolerance to biotic and abiotic stresses.
• Polyploidy results in reduced fertility and producing seedless varieties.
• If chromosomes is doubled by itself it is autopolyploidy.
• Triploid condition in Sugarbeets result in Vigour.
• Colchicine used to double the chromosomes. Eg. Triticale and Raphanobrassica

Question 13,
Biofortification is the breeding crops with
higher levels of nutrients. Justify it..
Answer:
Breeding of improved nutritional quality like
– Protein content and quality.
– Oil content and quality
– Vitamin Content
– Micro & Macro nutrient content.

• In 2000 – Maize hybrid had twice the nutrient value than the parents.
• Wheat – Atlass 66 having high protein content.
• Iron fortified rice can be developed.
• Vitamin A enriched vegetable.
• Vitamin C enriched vegetables and iron and calcium crops also developed.

Question 14.
Enumerate the New Breeding Techniques.
Answer:

• It is a collection of methods that could increase the development of new traits in plant breeding.
• It often involve genome editing.
• Cutting and modifying the genome during the repair process by tools like CRISPR.
• Genome editing to introduce changes in few base pairs using a technique called ODM.
• Transferring a gene from an identical or closely related species (Cisgenesis)
• Organising process that alter gene activity without altering the DNA itself.

Question 15.
Ramu and Somu are farmers. Ramu cultivated the crops by self fertilization method. Somu cultivated the crops from mixed population.
(i) Who will get new variety?
(ii) Write the advantage and disadvantages of their selection.
Answer:
(i) Somu will get the new variety. Because he had selected the mixed population method.

(ii) Advantages of self fertilization method:
The repeated self pollination from a single homozygous individual produces a variety that shows more homozygosity with respect to all genes.

(iii) Dis advantages:

• The major disadvantage of this type is that it never creates new genotypes.
• The plants produced are also less adaptible and less stable to the environmental fluctuations.

Advantages of Mixed population method
In this method, a large number of plants of similar phenotype (or) morphological characters are selected and their seeds are mixed together to constitute a newer variety’.

Disadvantages:
The disadvantage of mixed population method is that it is difficult to distinguish the hereditary variation from environmental variation .

Question 16.
Mention the benefits of seed treatment?
Answer:

• Prevents spread of plant disease
• Protects seed from seedling blights
• Improves germination
• Improves germination
• provides protection from storage insects
• controls soil insects.

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th Maths Guide Pdf Chapter 9 Limits and Continuity Ex 9.1 Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 11th Maths Solutions Chapter 9 Limits and Continuity Ex 9.1

In Problems 1 – 6, complete the table using calculator and use the result to estimate the limit.

Question 1.


Answer:

Question 2.


Answer:

Question 3.


Answer:

Question 4.


Answer:

Question 5.


Answer:

Question 6.


Answer:

Question 7.

Answer:

From the graph the value of the function at x = 3 is y = f(3) = 1

Question 8.


Answer:

From the graph the value of the function at x = 1 is y = f(1) = 3

Question 9.


Answer:

Question 10.


Answer:


From the graph the value of the function is y = f(1) = 3

Question 11.


Answer:

From the graph the value of the function at x = 3 the curve does not meet the line x = 3
∴ The value of the function is not defined at the point x = 3.
Hence \(\lim _{x \rightarrow 3} \frac{1}{x-3}\) does not exist at x = 3.

Question 12.

Answer:

From the graph x = 5 curve does not intersect the line x = 5
∴ The value of the function y = f(x) does not exist at x = 5.

Question 13.
\(\lim _{x \rightarrow 1}\) sin πx

Answer:
\(\lim _{x \rightarrow 1}\) sin πx
From the graph x = 1, the curve y = f(x) intersects the line x = 1 at x – axis.
∴ y = f(1) = 0
Hence \(\lim _{x \rightarrow 1}\) sin πx = 0

Question 14.
\(\lim _{x \rightarrow 0}\) sec x

Answer:
To find \(\lim _{x \rightarrow 0}\) sec x
Let y = f(x) = sec x
From the graph at x = 0 the curve intersect the y – axis.
At x = 0 we have y = 1
∴ \(\lim _{x \rightarrow 0}\) sec x = 1

Question 15.

Answer:

y = f(x) = sec x
From the graph at x = \(\frac{\pi}{2}\), the curve does not intersect the line x = \(\frac{\pi}{2}\)
At x = \(\frac{\pi}{2}\), the value of the function y = f(x) does not exist.
Hence does not exist.

Sketch the graph of f, then identify the values of x₀ for which \(\lim _{x \rightarrow x_{0}}\) f (x) exists.

Question 16.

Answer:

At x = 4 , the curve does not exist. Hence, except at x₀ = 4 , the limit of f(x) exists.

Question 17.

Answer:

From the figure when x = π, y = f(π) = 2. The function is not defined at x = π since sin x lies in the interval [ – 1, 1]
∴ The given function has limits at all points except at x = π


(π, 2) point is not possible since the range of the curve is [- 1 , 1] . Except x₀ = π, the curve has limits.

Question 18.
Sketch the graph of a function f that satisfies the given values:
(i) f(0) is defined
\(\lim _{x \rightarrow 0}\) f(x) = 4
f(2) = 6
\(\lim _{x \rightarrow 2}\) f(x) = 3
Answer:

(ii) f(-2) = 0
f(2) = 0
\(\lim _{x \rightarrow-2}\) f(x) = 0
\(\lim _{x \rightarrow 2}\) f(x) does not exist.
Answer:

Question 19.
Write a brief description of the meaning of the notation \(\lim _{x \rightarrow 8}\) f(x) = 25
Answer:
Given \(\lim _{x \rightarrow 8}\) f(x) = 25
By the definition of limit

∴ f(8^–) = f(8⁺) = 25

Question 20.
If f(2) = 4, can you conclude anything about the limit of f (x) as x approaches 2?
Answer:
No, f(x) = 4, It is the value of the function at x = 2
This limit doesn’t exists at x = 2
Since f(2) = 4
It need not imply that \(\lim _{x \rightarrow 2^{-}} f(x)=\lim _{x \rightarrow 2^{+}} f(x)\)
∴ we cannot conclude at x = 2

Question 21.
If the limit of f (x) as x approaches 2 is 4, can you conclude anything about f (2)? Explain reasoning.
Answer:
\(\lim _{x \rightarrow 2}\) f(x) 4 , \(\lim _{x \rightarrow 2^{-}}\) f(x) = \(\lim _{x \rightarrow 2^{+}}\) f(x) = 4
When x approaches 2 from the left or from the right f(x) approaches 4.
Given that \(\lim _{x \rightarrow 2^{-}}\) f(x) = \(\lim _{x \rightarrow 2^{+}}\) f(x) = 4
The existence or non-existence at x =2 has no leaving on the existence of the limit of f(x) as x approaches to 2.
∴ We cannot conclude the value of f(2).

Question 22.

Answer:

Question 23.
Verify the existence of \(\lim _{x \rightarrow 0}\) f(x), where

Answer:

From equations (1) and (2) we get
f(1^–) ≠ f(1⁺)
∴ The limit of f(x) does not exist.

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th English Guide Pdf Poem 3 Lines Written in Early Spring Text Book Back Questions and Answers, Summary, Notes.

Tamilnadu Samacheer Kalvi 11th English Solutions Poem 3 Lines Written in Early Spring

11th English Guide Lines Written in Early Spring Text Book Back Questions and Answers

1. Find words from the poem that convey the following ideas:

Question a.
connected together
Answer:
blended

Question b.
spread over the surface of the ground in a straggling manner
Answer:
tuft

Question c.
make out or understand
Answer:
measure

Question d.
slender woody shoots growing from branches or stems of trees
Answer:
twigs

2. Complete the summary of the poem by filling in the blanks with the words given below:

The poet, in a relaxed state of mind, is sitting in a (1) _______. He reflects on how his mood brings (2) _______ thoughts, which are inevitably followed by (3) _______ ones. He feels connected to all of nature, and senses an inherent joy in all (4) _______. He has faith in the fact that all the primroses and periwinkles around him (5) _______ the air they breathe. He feels that every bird in the grove moves with (6) _______. As the twigs catch the breezy air, they do so with the same pleasure (7) _______ all life on earth. This joy of nature seems to be heaven-sent. Nature’s holy plan is to offer joy and peace to all forms of life on earth. The poet’s pleasant train of thought slowly leads to the sad reflection of how mankind alone has wrought sorrow and (8) _______ upon itself. He firmly believes that man is meant to spend his days blissfully taking part in the vitality and joy surrounding him in (9) _______. He, therefore, concludes rhetorically, emphasizing that he has good reason to (10) _______the distress, man unnecessarily brings upon himself.
Answer:

1. Grove
2. Pleasant
3. Nature
4. Distressed
5. Calm
6. Bower
7. Breezy
8. Peace
9. Sorrow

3. Read the lines given below and answer the questions that follow:

(i) And ’tis my faith that every flower’
Enjoys the air it breathes…

Question (a)
What is the poet’s faith?
Answer:
The poet has faith that nature lives, breathes and enjoys its own presence. Twigs, birds, creepers all live in harmony with each other in absolute bliss and contentment.

Question (b)
What trait of Nature do we see here?
Answer:
The trait of Nature we see here is sharing and love of nature in all its creations.

(ii) And I must think, do all I can,
That there was pleasure there…

Question (a)
What did the poet notice about the twigs?
Answer:
The poet noticed it is happy to spread out its tender leaves to catch the breezy air.

Question (b)
What was the poet’s thought about them?
Answer:
The poet thought the twigs were experiencing the joy of their contact with the breezy air.

(iii) If this belief from heaven be sent,
If such be Nature’s holy plan.

Question (a)
What does ‘heaven’ refer to?
Answer:
Heaven refers to God.

Question (b)
Why does the poet call it ‘holy’?
Answer:
The poet believes that the harmonious, peaceful, and happy co-existence of birds, plants, trees, and brooks soothes the troubled mind of man. So, the poet feels as if he were inside a sacred place when he is in the woods. So, he calls the plan ‘holy’.

Additional Appreciation Questions:

1. I heard a thousand blended notes
While in a grove I sate reclined.

Question (a)
Where was the poet?
Answer:
The poet was in the grove.

Question (b)
What are blended notes?
Answer:
‘Blended notes’ relate to listening to the music of the breeze and the chirping of birds.

Question (c)
What does grove mean?
Answer:
Grove means a small area of land with a group of trees.

2. “To her fair works did nature link
The human soul that through me ran”

Question (a)
What is linked to human soul?
Answer:
Nature linked to human soul.

Question (b)
What are the fair works of nature?
Answer:
Human soul is the fair works of nature.

3. “Through primrose tufts, in that sweet bower
The periwinkle trail’d its wreaths”

Question (a)
What is primrose?
Answer:
It is a wild plant with yellow flowers.

Question (b)
What does ‘tufts’ mean?
Answer:
‘Tufts’ means bunches.

Question (c)
Where did the poet get to see this scene?
Answer:
The poet saw this beautiful scene in a grove.

4. Have I not reason to lament
What man has made of man?

Question (a)
What reason has the poet got to lament?
Answer:
He is very much distressed at the plight of humanity.

Question (b)
What is the solution to the problem?
Answer:
Man has to love the nature and live in harmony with nature.

4. Explain the following lines with reference to the context in about four to five sentences each:

I. In the sweet mood when pleasant thoughts
Bring sad thoughts to the mind.

Reference: These lines are from the poem “Lines Written in Early Spring” written by William Wordsworth.
Context: William Wordsworth was inspired in a small woodland grove, a landscape of beauty. He came upon this spot when walking near Alford village. While sensing the blissful mood and happiness of birds, plants, creepers and the murmuring brook, he juxtaposed what humans did to their kind in Napoleonic wars and amidst happy nature couldn’t help feeling sad. On that occasion, he said these words.

Explanation: The poet was captivated by the celestial beauty of the woodland near Alford village. The chirping of birds, the blooming flowers, and the brooks expressed their ecstasy of being alive. But their charm, peace, and contentment made Wordsworth compare the lives of war-mongers. Suddenly he became sad.
Comment: The poet beautifully portrays his mixed feelings.

II. The birds around me hopp’d and play’d
their thoughts I cannot measure.

Reference:
These lines are taken from Poem – “Lines Written in Early Spring”, Poet – “William Wordsworth”.
Context:
The poet utters these words while observing the beauty of nature.
Explanation:
The poet admires the beauty of nature while sitting in the grove. He observes that every creature is closely linked with nature. They not only feel happy on their own but also make others happy. He observes some birds around him which are hopping and playing happily. Though the poet cannot understand the thoughts in them, he is sure that they are happy.

III. Have I not reason to lament
What Man has made of man?

Reference: These lines are from the poem “Lines Written in Early Spring” written by William Wordsworth.
Context: William Wordsworth was inspired by a small woodland grove, a landscape of beauty. He came upon this spot when walking near Alford village. While sensing the blissful mood and happiness of birds, plants, creepers, and the murmuring brook, he juxtaposed what humans did to their kind in Napoleonic wars and amidst happy nature couldn’t help feeling sad. On that occasion, he said these words.

Explanation: William Wordsworth derived extreme pleasure listening to the songs of birds and voiceless communication of joy between plants, twigs, and flowers. Though he could not fathom the meaning, he realized the blissful state of nature. But he remembered the depravity of man which was evident in Napoleonic wars. He was fed up with man’s capacity to destroy innocent lives and property. So, he lamented “what man has made of man”.
Comment: The mixed feelings of happiness and sadness is well brought out.

5A. Read the following sets of lines and identify the figures of speech used in each extract:

a. Toherfair works did Nature link
The human soul that through me ran.
b.And ‘tis my faith that every flower
Enjoys the air it breathes.
c. What Man has made of Man?

5B. Read the poem once again. Identify the rhyme scheme and pick out the rhyming pairs of words:
Answer:
The rhyme scheme of the Poem is ab ab, ab ab………
Rhyming words are:

1. Notes – thoughts
2. Reclined – mind
3. Link – think
4. Ran – man
5. Bower – flower
6. Wreaths – breathes
7. Play’d – made
8. Measure – pleasure
9. Fan – can
10. Air – there
11. Sent – lament
12. Plan – man.

6. Answer the following in a sentence or two:

Question (a)
How does the poet feel while enjoying the beauty of Nature?
Answer:
The poet was in a sweet mood reclining in a grove. Hearing a thousand blended notes, his mind was filled with pleasant thoughts. He was very happy.

Question (b)
Does Nature affect a person’s thoughts and feelings? Explain.
Answer:
Yes, the poet finds everything happy – helping and sharing with each other. He feels that man alone is not a part of it.

Question (c)
How do people bring grief and sorrow to one another?
Answer:
People are jealous of one another’s wealth and possessions. One tries to harm the other by waging or provoking wars. Thus people bring grief and sorrow to one another.

Question (d)
Why does the poet think that the birds were happy?
Answer:
The way in which they hop and play makes the poet think that the birds were happy.

Question (e)
The poet finds joy in various objects of Nature. Explain
Answer:
The poet found joy in the primrose tufts, the sweet bower, the periwinkle, and the singing; birds.

Question (f)
Bring out the poet’s thoughts, while comparing Nature with human behaviour.
Answer:
Nature’s holy plan is that every creature should be happy but the humans fight with one another and lead a sorrowful life.

7. Complete the following sentences by choosing the best options:

Question (a)
The poet experiences sadness because of _______.
i. the blended notes are jarring
ii. Nature is filled with negativity
iii. he is worried about the destruction caused to Nature
iv. natural calamities occur frequently
Answer:
iii. he is worried about the destruction caused to Nature

Question (b)
The poem is set in a _______.
i. city
ii. Village
iii. grove
iv. Park
Answer:
iii. grove

Question (c)
The poem speaks of _______.
i. Mans plan to shape density
ii. Man seeking pleasure and riches
iii. Man indulging in wars and acts of destruction
iv. Mans fear of Nature
Answer:
iii. Man indulging in wars and acts of destruction

8. Answer in a paragraph of about 100 – 150 words:

Do you think the poet wants to say that man is unhappy because he has lost his link with nature and forgotten how to enjoy nature or because man is cruel to other men?

Paragraph:

The poet brings out varied reasons for the unhappiness of man. The main reason is he is cruel to other men. In this context, he brings forth the French revolution which had a great impact on the people of both France and Britain. The poet laments about this behaviour of man. Fie also observes that the flowers, birds, and trees have a close link with Nature and follow Nature’s holy plan of being together and sharing happiness. This view is made clear from the lines,

Through primrose tufts, in that sweet bower,
The periwinkle trail’d its wreaths;

The poet feels that man’s innate state must be close to nature. His heart is filled with pain when he thinks about the behaviour of man. His grief gets expressed from the lines,

And much it grieved my heart to think
What man has made of man?

He concludes that except man all other creatures are happy as they have a close link with nature and they share and care for each other. He is not able to find a positive answer for what man has made of man. That is why he says,

Have I not reason to lament
What man has made of man?

ஆசிரியரைப் பற்றி:

வில்லியம் வேர்ட்ஸ்வொர்த் (1770-1850) மிகச்சிறந்த ஆங்கிலக் கவிஞர். சாமுவேல் டெய்லர் கோல்ரிட்ஜிடன் இணைந்து Lyrical Ballads என்ற கவிதை தொகுப்பை வெளியிட்டதன் மூலம் ஆங்கில இலக்கியத்தில் புதிய ரொமாண்டிக் காலத்தை தொடங்கிவைத்தார்.

பிரிட்டனின் அரசவைக் கவிஞராக 1984ம் ஆண்டு முதல் வாழ்நாள் இறுதி வரை இருந்து வந்தார். இவர் இயற்க்கை கவிஞர் என்றே எல்லோராலும் அறியப்பட்டடார். “Daffodils”, “The Solitary Reaper”, “To the cuckoo'” “The tables turned”, Lines composed a few miles above Tintern Abbey ஆகியவை இவரின் புகழ் பெற்ற கவிதைகள்.

கவிதையைப் பற்றி:

இக்கவிதையில் கவிஞர் மனிதன் தன் சக மனிதனுக்கு செய்யும் இடையூறுகளை நினைத்து மனம் வருந்துகிறார். இயற்கை என்னும் அற்புதத்தை இறைவன் நமக்காக படைத்துள்ளார். அதில் ஒன்றாக கலந்து கவிஞர் மகிழ்ந்தாலும் மனிதர்களின் செயல்பாடுகள் இயற்க்கைக்கு எதிராக இருப்பதை நினைத்து .மனம் வெதும்புகிறார்.

Lines Written in Early Spring Summary in Tamil

சோலையொன்றில் நான் சாய்ந்தமர்ந்திருந்த போது
ஆயிரம் கானங்கள் கலந்த இசையைக் கேட்டேன்.
அவ்வினிய தருணத்தில் இன்ப நினைவுகள்
சுமந்து வந்ததோ துன்ப நினைவுகள்.
என்னே இயற்கையின் கைவண்ணம்!

தன்னையே என் ஆன்மாவுடன் இணைந்து
துன்பறுத்துகிறது என் இதயத்தை – நினைக்க
வேண்டுகிறது மனிதன் மனிதனைக்கொண்டு உருவாக்கியதை
பிரிம் ரோஸ் மலர்களிடையே அம் மர நிழலடியில்
பெரிவிங்கிள் தன் ஊதா பூக்களை பரவ விட்டிருக்கிறது.

என் மனம் கூறுகிறது, ஒவ்வொரு பூவும்
அதன் மணத்தை சுவாசத்தில் உணர்த்து மகிழும் என்று.
என்னைச் சுற்றி பறவைகள் துள்ளி விளையாடுகின்றன.
அதன் மன அலைகளோ அளவிட முடியாதவை.
ஆனால் அவற்றின் மிக எளிய அசைவுகள் கூட
மகிழ்வின் உச்சமாக மாறுகின்றன.
மலர் மொட்டுகள் இதழ் விரித்தன.

மணம் வீசும் தென்றல் தழுவிட
நானும் சிந்தித்து செயலாற்ற வேண்டும்
இங்கு இருக்கும் மகிழ்வில் கலந்திட
இந்நம்பிக்கை விண்ணின்று அனுப்பப்பட்ட தென்றல்
இது இயற்கையின் தூய திட்டமென்றால்,
நான் புலம்புவதற்கு காரணமாக இல்லை,
மனிதன் மனிதனைக் கொண்டு உருவாக்கியதை எண்ணி.

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th English Guide Pdf Poem 2 Confessions of a Born Spectator Text Book Back Questions and Answers, Summary, Notes.

Tamilnadu Samacheer Kalvi 11th English Solutions Poem 2 Confessions of a Born Spectator

11th English Guide Confessions of a Born Spectator Text Book Back Questions and Answers

1. Based on your understanding of the poem, answer the following questions in a sentence or two:

Question a.
Why does the poet feel glad that he does not play any game?
Answer:
The poet feels glad that he was not a player but only a spectator. He is glad because of the risk of injuring himself and others is more if he becomes a player.

Question b.
Do you think the narrator is heroic? Why?
Answer:
No, just watching the heroic deeds of enthusiastic athletes is not considered heroic.

Question c.
The poet is satisfied just watching the heroic deeds of others. What could be the reason?
Answer:
The poet is very sensitive. He derives vicarious pleasure on seeing the play of all the players. He is not after glory, medals, and not interested in inflicting injury on any opponent. So, he is happy staying out of all rough games.

Question d.
The poet does not wish to exchange position with the runners. Why?
Answer:
The athletes never care for the feelings of others when they play enthusiastically. So the poet does not wish to exchange position with them.

Question e.
Are the athletes conscious of the feelings of others? Why do you say so?
Answer:
No, the athletes are zealous in their endeavour to win. In the process, they go to the extent of maiming fellow players. The player’s focus is mostly on winning and he is naturally not conscious of the feelings of others.

Question f.
Why would the referee ask whether there was a doctor in the stands? What stands is he referring to?
Answer:
The referee would ask for a doctor when any athlete cracks his wrist or got injured in any way. Stands here refer to the stadium or boxing ring.

Question g.
Why does the poet prefer to buy tickets worth their weight in radium? Bring out the significance of the metal referred to here?
Answer:
Radium is more expensive than diamonds. It is a rare metal discovered by Madam Curie. The poet was ready to buy tickets as expensive as radium just to stay as a spectator.

2. Read the poem again and complete the summary using the words given in the box: (Text Book Page No. 54)

In the poem Confessions of a Born Spectator, Ogden Nash talks about how people choose different sports in their lives or decide to become athletes. While admiring the talents of athletes and sportsmen, the poet (i)_________ that he is glad that he is neither a sportsman nor an athlete. Children have different (ii) _________ and wish to play various games. Each child has in mind something in particular, but the narrator is (iii) _________ he is not one of the players. Though the narrator (iv) _________ the talents of all athletes, he derives satisfaction from watching them but does not wish to (v) _______ places with them. He also sometimes regrets that (vi) _______ athletes play rough games without caring for the feelings of their sporting rivals. He feels that good sense and caution win over ego. The narrator wholeheartedly offers (vii) _______ the modest (viii) ___________ of athletes. Ultimately the narrator is (ix) _______ that he himself is not an athlete.
Answers:
(i) Confesses
(ii) Aims
(iii) Glad
(iv) Admires
(v) Exchange
(vi) Zealous
(vii) Thanksgiving
(viii) Physiques
(ix) Satisfied

3. Read the poem and answer the following in a short paragraph of 8 – 10 sentences each: (Text Book Page No. 55)

Question a./b.
How does the poet establish the victory of common sense over ego?/ The poet does not wish to exchange places with athletes. How does she justify his view?
Answer:
The poet readily considers himself as a Born Spectator. He admires the talents of the athletes who are skillful in varied sports. That is running ninety yards, knocking the champion to the floor, taking hold of the horse to make it win, etc. He satisfies his love for sports by watching the heroic deeds of sportspersons.

His ego gets slightly disturbed while watching such heroic deeds which induces him to act as an athlete. Thus arise a struggle between his ego and common sense. But when he sees athletes playing, so rough injuring others and never bothers about the opponents’ feeling his common sense has its victory.

Question c.
According to the poet, what contributes most to the injuries sustained by the athletes?
Answer:
According to the poet, the athletes perform heroic deeds and risk their lives to the maximum to attain success. They have to overcome many hurdles before they taste success. Apart from this, they get hurt physically too in many ways. So the poet feels that there is nothing wrong to buy tickets worth their radium.

As they are very active like radium let them be given a huge sum of money like that for radium. Being a spectator and realizing the hard effort of the athlete the poet readily feels that he can share everything with them. It is in this way one can contribute to the injuries sustained by the athletes.

4. Read the given lines and answer the questions that follow in a sentence or two:

a. With all my heart I do admire
Athletes who sweat for fun or hire

Question i.
Whom does the poet admire?
Answer:
The poet admires the athletes.

Question ii.
For what reasons do the athletes sweat?
Answer:
The athletes sweat either for fun or for monetary benefits.

b. Well, ego it might be pleased enough
But zealous athletes play so rough

Question i.
What pleases the ego?
Answer:
The daring spirit of the athletes pleases the ego.

Question ii.
Why are athletes often rough during play?
Answer:
They are rough as they play enthusiastically towards their victory.

c. When officialdom demands
Is there a doctor in the stands?

Question i.
Why are doctors called from stands by the sponsors?
Answer:
Doctors are called from stands when players get injured.

Question ii.
Why does the poet make such an observation?
Answer:
The poet himself is present as a spectator there in the stadium. He is not willing to exchange places with the athletes.

C. When snaps the knee and cracks the wrist:

Question i.
Identify and explain the use of the literary device in this line.
Answer:
The literary device used here is onomatopoeia. It imitates the natural sound of a thing. Here the snapping sound of the knee and the cracking sound of the wrist is explained.

Additional Appreciation questions:

1. “One infant grows up and becomes a Jockey
Another plays basketball or hockey,”
This one the prize ring hates to enter
That one becomes a tackle or center
I am just glad as I glad can be.

Question a.
What does ‘Jockey’ refer to?
Answer:
Jockey refers to horse riding.

Question b.
Who is playing the game?
Answer:
The infant is playing the game.

Question c.
Who is glad?
Answer:
The spectator is glad.

Question d.
Why is he glad?
Answer:
He is glad because he needn’t compete in the field.

Question e.
Whom does ‘they refer’ to?
Answer:
They refer to athletes.

Question f.
What is the figure of speech used in the 5th line?
Answer:
Simile.

2. Now A runs ninety yards to score
B knocks the champion to the floor
Cracking vertebrae and spines
Lashes his steed across the line:

Question a.
Why does ‘A’ run ninety yards?
Answer:
‘A’ runs ninety yards to win the match.

Question b.
Why does ‘B’ knock ‘A’?
Answer:
‘B’ disturbs ‘A’ because he doesn’t want A’ to win.

Question c.
Why does ‘B’ lash across the line?
Answer:
‘B’ lashes across the line to get victory over A.

Question d.
Who cracks whose vertebrae and spines?
Answer:
‘B’ cracks ‘A’s vertebrates and spines.

3. When swollen eye meets gnarled fist
When snaps the knee and cracks the wrist
When officialdom demands,
Is there a doctor in the stands?

Question a.
Why are the eyes swollen?
Answer:
The opponent is fierce enough to inflict injury on the other’s eye in the boxing event.

Question b.
What encounters the gnarled fist?
Answer:
The athletes swollen eyes encounter the gnarled fist during the contest.

4. “And reassure me a new
That you are not me and I am not you”

Question a.
Why does the poet repeat the line?
Answer:
He repeats the line again to stress the fact that each and every individual is unique.

Question b.
Whom does he assure?
Answer:
He assures himself.

Poetic lines-(Figures of Speech):

5A. Explain the following with reference to the context in about 50 – 60 words each:

i. I am just glad as glad can be.
That I am not them, that they are not me ………

Reference:
These lines are taken from Poem – “Confessions of a Born Spectator”, Poet – “Ogden Nash”.
Context:
The poet says these words when he feels happy of not being an athlete.
Explanation:
The poet talks about how people choose different sports in their lives or decide to become athletes. While admiring the talents of athletes and sportsmen he confesses that he is happy that he is not a sportsman.

ii. They do not ever in their dealings
Consider one another’s feelings

Reference:
These lines are taken from Poem – “Confessions of a Born Spectator”, Poet – “Ogden Nash”.
Context:
Here the poet speaks about the behaviour of the athletes while playing.
Explanation:
The athletes used to play rough games when they play enthusiastically. In this regard, they never care for the feelings of their sporting rivals. The poet regrets this behaviour of the athletes.

iii. Athletes, I’ll drink to you,
Or eat with you,
Or anything except competing with you

Reference:
These lines are taken from Poem – “Confessions of a Born Spectator”, Poet – “Ogden Nash”.
Context:
Here the poet expresses his view of not competing with sportspersons in any way.
Explanation:
The poet is very clear of the view that he is a Born Spectator and not a sports person. He is ready to share everything with the athletes like spending gala time, dining together with them, etc. but is not ready to compete with them in their sports activities.

5B. Read the poem and complete the table with suitable rhyming words:

Question 1.

Answer:

Question 2.

Answer:

5C. Underline the alliterated words in the following lines: 

Question i.
For this most modest physiques…
Answer:
For this most modest physiques…

Question ii.
They do not ever in their dealings…
Answer:
They do not ever in their dealings…

5D. Find out the rhyme scheme of the given stanza:

Question 1.
One infant grows up and becomes a jockey
Another plays basketball or hockey
This one the prize ring hates to enter
That one becomes a tackle or center…
Answer:
The rhyme scheme of the poem is aa, bb.

Listening Activity:

Question 1.
Tejaswini Sawant is an Indian _______.
a) shooter
b) boxer
c) cricketer
Answer:
a) shooter

Question 2.
She represented India at the 9th South Asian Sports Federation Games in _______.
a) 2001
b) 2002
c) 2004
Answer:
c) 2004

Question 3.
In 2006, she won a Gold medal in the _______.
a) Commonwealth Games
b) Olympic Games
c) Asian Games
Answer:
a) Commonwealth Games

Question 4.
She became a world champion in the 50m Rifle Prone game held in _______.
a) Germany
b) Russia
c) India
Answer:
a) Germany

Question 5.
Tejaswini was the first Indian woman shooter to win a _______ medal at the World Championship in the 50m
rifle prone game.
a) gold
b) silver
c) bronze
Answer:
a) Gold

7. Paragraph:

In the poem “Confessions of a Born Spectator” the poet talks about how people choose to opt for different sports in their lives or decide to become athletes. At the same time, he confesses that he is glad that he is neither a sports person nor an athlete. He admires the talents of all athletes and derives great satisfaction watching them. This is understood from the lines

My limp and bashful spirit feeds
on other people’s heroic deeds.

Being a Born Spectator he does not wish to exchange places with the athletes at any cost. He doesn’t like to get injured in any way. Moreover, he regrets over the fact that Zealous athletes play rough games without even caring for each other’s feelings. The poet conveys this idea through the lines

They do not ever in their dealings
Consider one another’s feelings.

He feels that good sense and caution win over ego. He offers thanksgiving the modest physiques of athletes as they risk their lives to a great extend like snapping their knees and cracking their wrist etc. This shows that the athletes take a lot of trials to achieve the desired results. The poet is always ready to share a drink or a meal with the athletes. In fact, he is ready to do anything except competing with them. Ultimately the poet is satisfied that he himself is not an athlete which is clearly proved from the lines

And reassure me a new
That you are not me and I’m not you.

கவிஞரைப் பற்றி:

Frederic Ogden Nash என்பவர் ஒரு அமேரிக்க கவிஞர். இவர் 500ற்கும் மேற்பட்ட நகைச்சுவை கவிதைகளை இதுவரை எழுதியுள்ளார். இவரது கவிதைகளில், கதைகளில் பயன்படுத்திய எதுகை அமைப்பு முறை இவரை மிகச்சிறந்த நகைச்சுவை கவிஞராக அமேரிக்காவில் அடையாளம் கட்டப்பட்டுள்ளார். இவரின் நினைவாக அமேரிக்காவில் தபால்தலை வெளியிடப்பட்டிருக்கிறது.

கவிதையைப் பற்றி:

எந்த ஒரு போட்டியாக இருந்தாலும் அதில் இருவேறு செய்திகள் அடங்கி இருக்கும். ஒன்று விளையாட்டு வீரர், மற்றொன்று பார்வையாளர். வீரர் விளையாட்டில் கலந்து தன் திறமையை வெளிகாட்டுவார் பார்வையாளர் அதை வேடிக்கை பார்ப்பார். வீரர் காயப்பட்டு, எழும்புகள் உடைக்கப்பட்டு, வீரத்தை வெளிகாட்டுகிறார்.

ஆனால் பார்வையாளர் வெளியில் நின்று வேடிக்கை பார்த்து இரசிக்கிறார். இந்த கவிதையில் விளையாட்டு வீரர்களை வேடிக்கை பார்த்து இரசிக்கும் கவிஞர் அதை நகைச்சுவையாக பேசுகிறார்.

Confessions of a Born Spectator summary in Tamil

ஒரு குழந்தை வளர்ந்து ஒரு குதிரை வீரனாக (Jockey) மாறுகிறது.
மற்றொன்று கூடைப்பந்து அல்லது ஹாக்கி விளையாடுகிறது.
இது குத்துச் சண்டை வளையத்தில் (Prize Ring) நுழைய மறுக்கிறது.
அது பந்தைய வீரனாக அல்லது நடுவராகிறது.
மகிழ்ச்சியாக இருப்பதால் நான் மகிழ்ச்சியடைகிறேன்.
நான் அவர்களும் இல்லை, அவர்கள் அனைவரும் நான் இல்லை.
என் முழு உள்ளத்தோடு நான் மகிழ்கிறேன் (பாராட்டுகிறேன்)

வேடிக்கை அல்லது ஊதியத்திற்கு வியர்வை சிந்தும் வீரர்களை நான் மதிக்கிறேன்,
அவர்கள் களத்தில் பகட்டான (gaudy pomp) ஆடை அணிந்து கொள்கிறார்கள்.
கரடுமுரடாக, ஆர்வமாக விளையாடும் போது
ஒரவரக்கொருவர் காயம் உண்டாக்கி கொள்கிறார்கள்.
எனது குறைகளும் ஞானமும் எனது ஆற்றலை மற்ற வீரர்களின்
வீர செயல்களால் ஊக்கமளிக்கப்படுகிறது.

இப்போது A தொண்ணூறு தெலைதூரம் வெற்றிபெற ஓடுகிறார்
B வெற்றியாளரை தரையில் தள்ளிவிடுகிறார்.
அவனது முதுகையும் முதுகெலும்புகளையும் உடைத்துக்கொண்டு
பாதை (line) முழுவதும் தனது குதிரையை சவுக்கால் அடித்து (Steed) வசைப்படுகிறான் (lashes)
நீங்கள் என் விடா முயற்சி ஏதேனும்
ஒரு இலக்கை அடைய வைக்கும் என நினைப்பீர்கள்
ஆம் நன்றாக விடாமுயற்சி போதுமானமதாக இருக்கலாம்.

ஆனால் ஆர்வமுள்ள விளையாட்டு வீரர்கள் மிகவும் கடினமானவர்கள்
அவர்கள் எப்போதும் உணர்ச்சிகளில் வெல்பவர்கள் அல்ல
ஒருவரின் உணர்வுகளினால் வெல்கிறார்கள்.
எனக்கு துன்பம் வரும்போதெல்லாம்
என்னுடைய புத்திசாலித்தனம், விவேகம் வெற்றி பெறுகிறது.

வீங்கிய கண்கள் கரடுமுரடான முட்டியை சந்திக்கும் போது,
என்னை வெற்றியடையச் செய்வதை என்னி மகிழ்கிறேன்
முழங்கால்கள் மற்றும் மணிக்கட்டுகள் விரிசல் ஏற்படம் போது, நடுவர் கேட்கிறார்
அங்கே மருத்துவர் இருக்கிறாரா? என்று
என் ஆண்மா எளிமையான, உண்மையான நன்றிகளை சாதாரண உடலமைப்பிற்காக சொல்கிறது.

தடகள வீரர்களே நான் உங்களுடன் குடிக்கிறேன்
அல்லது உங்களுடன் சாப்பிடுகிறேன்
உங்களுடன் போட்டியிடும் எதையும் தவிர
அரங்கில் உங்கள் குதுகளத்தை (gambol) பார்க்க வேண்டும்
என்பதற்காக ரேடியம் மதிப்புள்ள டிக்கட்டை வாங்குகிறேன்.

இழந்துவிட்ட நம்பிக்கையை புதிதாக மறுபடியும் உறுதி செய்கிறேன்
நான் நீங்கள் இல்லை,
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Tamilnadu State Board New Syllabus Samacheer Kalvi 11th Maths Guide Pdf Chapter 8 Vector Algebra – I Ex 8.3 Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 11th Maths Solutions Chapter 8 Vector Algebra – I Ex 8.3

Question 1.
Find \(\vec{a}\) . \(\vec{b}\) when
(i) \(\vec{a}\) = î – 2ĵ + k̂ and \(\vec{b}\) = 3î – 4ĵ – 2k̂
(ii) \(\vec{a}\) = 2î + 2ĵ – k̂ and \(\vec{b}\) = 6î – 3ĵ + 2k̂
Answer:
(i) \(\vec{a}\) = î – 2ĵ + k̂ and \(\vec{b}\) = 3î – 4ĵ – 2k̂
\(\vec{a}\) . \(\vec{b}\) = (î – 2ĵ + k̂) . (3î – 4ĵ – 2k̂)
= (1) (3) + (-2) (-4) + (1) (-2)
= 3 + 8 – 2
= 9

(ii) \(\vec{a}\) = 2î + 2ĵ – k̂ and \(\vec{b}\) = 6î – 3ĵ + 2k̂
\(\vec{a}\) . \(\vec{b}\) = (2î + 2ĵ – k̂) . (6î – 3ĵ + 2k̂)
= (2) (6) + (2) (-3) + (-1) (2)
= 12 – 6 – 2 = 12 – 8 = 4

Question 2.
Find the value λ for which the vectors \(\vec{a}\) and \(\vec{b}\) are perpendicular, where
(i) \(\vec{a}\) = 2î + λĵ – k̂ and \(\vec{b}\) = î – 2ĵ + 3k̂
(ii) \(\vec{a}\) = 2î + 4ĵ – k̂ and \(\vec{b}\) = 3î – 2ĵ + λk̂
Answer:
When \(\vec{a}\) and \(\vec{b}\) are ⊥^r then \(\vec{a} \cdot \vec{b}\) = 0
\(\vec{a}\) ⊥^r \(\vec{b}\) ⇒ \(\vec{a} \cdot \vec{b}\) = 0
(i) (2) (1) + (λ) (-2) + (1) (3) = 0 ⇒ λ = 5/2
(ii) (2) (3) + (4) (-2) + (-1) (λ) = 0
6 – 8 – λ = 0
-λ – 2 = 0 ⇒ -λ = 2 ⇒ λ = -2

Question 3.

Answer:

Question 4.
Find the angle between the vectors
(i) 2î + 3ĵ – 6k̂ and 6î – 3ĵ + 2k̂
(ii) î – ĵ and ĵ – k̂
Answer:
(i) 2î + 3ĵ – 6k̂ and 6î – 3ĵ + 2k̂
Let θ be the angle between the given vectors, then

(ii) î – ĵ and ĵ – k̂
Let θ be the angle between the given vectors, then

Question 5.

Answer:

Question 6.
Show that the vectors \(\vec{a}\) = 2î + 3ĵ + 6k̂ \(\vec{b}\) = 6î + 2ĵ – 3k̂ and \(\vec{c}\) = 3î – 6ĵ + 6k̂ are mutually orthogonal.
Answer:
Given \(\vec{a}\) = 2î + 3ĵ + 6k̂ \(\vec{b}\) = 6î + 2ĵ – 3k̂ and \(\vec{c}\) = 3î – 6ĵ + 6k̂
\(\vec{a}\) . \(\vec{b}\) = (2î + 3ĵ + 6k̂) . (6î + 2ĵ – 3k̂)
= (2) (6) + (3) (2) + (6) (-3)
= 12 + 6 – 18
= 0
∴ \(\vec{a}\) and \(\vec{a}\) are perpendicular.

\(\vec{b}\) . \(\vec{c}\) = (6î + 2ĵ – 3k̂) . (3î – 6ĵ + 6k̂)
= (6) (3) + (2) (- 6) + (-3) (2)
= 18 – 12 – 6
= 0
∴ \(\vec{b}\) and \(\vec{c}\) are perpendicular.

\(\vec{c}\) . \(\vec{a}\) = (3î – 6ĵ + 6k̂) . (2î + 3ĵ + 6k̂)
= (3) (2) + (-6) (3) + (2) (6)
= 6 – 18 + 12
= 0
∴ \(\vec{c}\) and \(\vec{a}\) are perpendicular.
Hence \(\vec{a}\), \(\vec{b}\), \(\vec{c}\) are mutually perpendicular vectors.

Question 7.
Show that the vectors – î – 2ĵ – 6k̂, 2î – ĵ + k̂ and – î + 3ĵ + 5k̂ from a right-angled triangle.
Answer:

CA = \(\sqrt{1+9+25}\) = \(\sqrt{35}\)
AB ≠ BC + CA
∴ The given vectors form a triangle, Also
AB² = 41, BC² = 6, CA² = 35
AB² = BC² + CA²
∴ ∆ ABC is a right angled triangle.

Question 8.

Answer:

Question 9.
Show that the points (2, – 1, 3), (4, 3, 1), and (3, 1, 2) are collinear.
Answer:
Let the given points be
A (2, -1, 3), B (4, 3, 1) and C (3, 1, 2)


AB = 2√6, BC = √6, CA = √6
BC + CA = √6 + √6 = 2√6
∴ BC + CA = BA = 2√6
Hence the given points A, B, C are collinear.

Question 10.
If \(\vec{a}\), \(\vec{b}\) are unit vectors and θ is the angle between them, show that
(i)
(ii)
(iii)
Answer:
Given \(\vec{a}\) and \(\vec{b}\) are unit vectors.
∴ |\(\vec{a}\)| = 1 and |\(\vec{b}\)| = 1

(i)

(ii)

(iii)

Question 11.

Answer:

Question 12.
Find the projection of the vector î + 3ĵ + 7k̂ on the vector 2î + 6ĵ + 3k̂
Answer:
The given vectors are î + 3ĵ + 7k̂ and 2î + 6ĵ + 3k̂
Projection of î + 3ĵ + 7k̂ on 2î + 6ĵ + 3k̂ is

Question 13.
Find λ, when the projection \(\vec{a}\) = λî + ĵ + 4k̂ on \(\vec{b}\) = 2î + 6ĵ + 3k̂ is 4 units.
Answer:
The given vectors are
\(\vec{a}\) = λî + ĵ + 4k̂ , \(\vec{b}\) = 2î + 6ĵ + 3k̂
Also given that projection of \(\vec{a}\) and \(\vec{b}\) is 4 units.

Question 14.

Answer: