{"id":24230,"date":"2020-12-18T06:12:48","date_gmt":"2020-12-18T06:12:48","guid":{"rendered":"https:\/\/samacheer-kalvi.com\/?p=24230"},"modified":"2021-12-06T15:56:34","modified_gmt":"2021-12-06T10:26:34","slug":"samacheer-kalvi-9th-science-guide-chapter-22","status":"publish","type":"post","link":"https:\/\/samacheer-kalvi.com\/samacheer-kalvi-9th-science-guide-chapter-22\/","title":{"rendered":"Samacheer Kalvi 9th Science Guide Chapter 22 World of Microbes"},"content":{"rendered":"

Tamilnadu State Board New Syllabus Samacheer Kalvi 9th Science Guide<\/a> Pdf Chapter 22 World of Microbes Text Book Back Questions and Answers, Notes.<\/p>\n

Tamilnadu Samacheer Kalvi 9th Science Solutions Chapter 22 World of Microbes<\/h2>\n

9th Science Guide World of Microbes Text Book Back Questions and Answers<\/h3>\n

\"Samacheer<\/p>\n

I. Choose the correct answer :<\/span><\/p>\n

Question 1.
\nWhich of the following is transmitted through air?
\n(a) Tuberculosis
\n(b) Meningitis
\n(c) Typhoid
\n(d) Cholera
\nAnswer:
\n(a) Tuberculosis<\/p>\n

Question 2.
\nOne of the means of indirect transmission of a disease is
\n(a) sneezing
\n(b) coughing
\n(c) vectors
\n(d) droplet infection
\nAnswer:
\n(c) vectors<\/p>\n

\"Samacheer<\/p>\n

Question 3.
\nDiptheria affects the
\n(a) lungs
\n(b) throat
\n(c) blood
\n(d) liver
\nAnswer:
\n(b) Throat<\/p>\n

Question 4.
\nThe primary organ infected during tuberculosis is
\n(a) bone marrow
\n(b) intestine
\n(c) spleen
\n(d) lungs
\nAnswer:
\n(d) lungs<\/p>\n

\"Samacheer<\/p>\n

Question 5.
\nMicrobes that generally enter the body through nose are likely to affect
\n(a) gut
\n(b) lungs
\n(c) liver
\n(d) lymph nodes
\nAnswer:
\n(b) lungs<\/p>\n

Question 6.
\nThe organ affected by jaundice is
\n(a) liver
\n(b) lungs
\n(c) kidney
\n(d) brain
\nAnswer:
\n(a) liver<\/p>\n

\"Samacheer<\/p>\n

Question 7.
\nPoliomyelitis virus enters the body through
\n(a) skin
\n(b) mouth and nose
\n(c) ears
\n(d) eye
\nAnswer:
\n(b) mouth and nose<\/p>\n

II. Fill in the blanks:<\/span><\/p>\n

1. …………….. break down organic matter and animal waste into ammonia.
\nAnswer:
\nDecomposers<\/p>\n

2. Typhoid fever is caused by ………………
\nAnswer:
\nsalmonella typhi<\/p>\n

\"Samacheer<\/p>\n

3. H1N1 virus causes……………..
\nAnswer:
\nswine flu<\/p>\n

4. …………….. is a vector of viral disease dengue.
\nAnswer:
\nAedes aegypti mosquito<\/p>\n

5. …………….. vaccine gives considerable protection against tuberculosis.
\nAnswer:
\nBCG<\/p>\n

\"Samacheer<\/p>\n

6. Cholera is caused by…………….. and malaria is caused by………………
\nAnswer:
\nbacteria (Vibrio cholera), protozoa (plasmodium)<\/p>\n

III. Expand the following:<\/span><\/p>\n

    \n
  1. ORS – Oral Rehydration Solution.<\/li>\n
  2. HIV – Human Immunodeficiency Virus.<\/li>\n
  3. DPT – Diphtheria Pertussis Tetanus.<\/li>\n
  4. WHO – World Health Organisation.<\/li>\n
  5. BCG – Bacillus Calmette Guerin.<\/li>\n<\/ol>\n

    IV. Pick out the odd one :<\/span><\/p>\n

      \n
    1. AIDS, Retrovirus, Lymphocytes, BCG, – BCG.<\/li>\n
    2. A bacterial disease, Rabies, Cholera, Common cold, and Influenza – Cholera.<\/li>\n<\/ol>\n

      V. State whether True or False. If false, correct the statement:<\/span><\/p>\n

      1. Rhizobium, associated with root nodules of leguminous plants fixes atmospheric nitrogen.
      \nAnswer:
      \nTrue.<\/p>\n

      \"Samacheer<\/p>\n

      2. Non-infectious diseases remain confined to the person who develops the disease and do not spread to others.
      \nAnswer:
      \nTrue.<\/p>\n

      3. The process of vaccination was developed by Jenner.
      \nAnswer:
      \nTrue.<\/p>\n

      4. Hepatitis B is more dangerous than Hepatitis A.
      \nAnswer:
      \nTrue.<\/p>\n

      \"Samacheer<\/p>\n

      VI. Match the following :<\/span><\/p>\n\n\n\n\n\n\n
      Swine flu<\/td>\nHuman Papilloma vims Influeuza vims HINl<\/td>\n<\/tr>\n
      Genital warts<\/td>\nHuman Immunodeficiency Vims<\/td>\n<\/tr>\n
      AIDS<\/td>\nMycobacterium<\/td>\n<\/tr>\n
      Tuberculosis<\/td>\nInfluenza vims HINl<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

      Answer:<\/p>\n\n\n\n\n\n\n
      Swine flu<\/td>\nInfluenza vims HINl<\/td>\n<\/tr>\n
      Genital warts<\/td>\nHuman Papilloma vims<\/td>\n<\/tr>\n
      AIDS<\/td>\nHuman Immunodeficiency Vims<\/td>\n<\/tr>\n
      Tuberculosis<\/td>\nMycobacterium<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

      VII. Define the following:<\/span><\/p>\n

      1. Pathogen
      \n2. Bacteriophages
      \n3. Vaccines
      \n4. Prions
      \nAnswer:
      \n1. Pathogen – A pathogen is a biological agent that causes disease due to its host E.g. Bacteria, Virus, etc.,
      \n2. Bacteriophages – Virus that infect bacterial cells E.g. T4 bacteriophage.
      \n3. Vaccines – Preparation of antigenic proteins of pathogens (weakened or killed) which on inoculation into a healthy person provides temporary \/ permanent immunity against a particular disease.
      \n4. Prions – Prions are viral particles which contain only proteins. They do not contain nucleic acid.<\/p>\n

      \"Samacheer<\/p>\n

      VIII. Answer very briefly :<\/span><\/p>\n

      Question 1.
      \nDistinguish between Virion and Viroid.
      \nAnswer:
      \nVirion<\/p>\n

        \n
      1. Simple vims particle.<\/li>\n
      2. Grow and multiply in living cells.<\/li>\n<\/ol>\n

        Viriod<\/p>\n

          \n
        1. The protein-free pathogenic RNA of vims.<\/li>\n
        2. Found in plant cells and causes disease in plants.<\/li>\n<\/ol>\n

          Question 2.
          \nName the vector of the malarial parasite. Mention the species of malarial parasite which cause malignant and fatal malaria.
          \nAnswer:
          \nThe vector of the malarial parasite is the female Anopheles mosquito.
          \nMalaria caused by Plasmodium falciparum is malignant and fatal.<\/p>\n

          \"Samacheer<\/p>\n

          Question 3.
          \nWhat is triple antigen? Mention the disease which can be prevented by using the antigen.
          \nAnswer:
          \nTriple antigen : It is combination of three vaccines (DPT).
          \nPreventable diseases : Diptheria, Pertussis (Whooping cough) and Tetanus.<\/p>\n

          Question 4.
          \nName the chronic diseases associated with respiratory system.
          \nAnswer:
          \nChronic diseases associated with the respiratory system are; Diptheria, Whooping Cough, Tuberculosis.<\/p>\n

          Question 5.
          \nName the organism causing diarrhoeal disease and give one precaution against it.
          \nAnswer:<\/p>\n

            \n
          1. Rotavirus.<\/li>\n
          2. Precaution : Proper sanitation and hygiene.<\/li>\n<\/ol>\n

            \"Samacheer<\/p>\n

            Question 6.
            \nName two common mosquitoes and the diseases they transmit.
            \nAnswer:
            \nAnopheles mosquito and Aedes aegypti mosquito are common mosquitoes that transmit malaria, Chikungunya and Dengue.<\/p>\n

            IX. Answer briefly :<\/span><\/p>\n

            Question 1.
            \nGive an account of classification, of bacteria based on the shape.
            \nAnswer:
            \nBacteria are microscopic, single-celled prokaryotic organisms without a nucleus and other cell organelles. Although the majority of bacterial species exist as single-celled forms, some appear to be filaments of loosely joined cells. The size varies from less than 1 to 10 \u00b5m in length and 0.2 to 1 \u00b5m micrometer in width.
            \nBased on the shapes, bacteria are grouped as:<\/p>\n

              \n
            1. Spherical shaped bacteria called cocci (or coccus for a single cell).<\/li>\n
            2. Rod-shaped bacteria called bacilli (or bacillus for a single cell).<\/li>\n
            3. Spiral shaped bacteria called spirilla (or spirillum for single cell)<\/li>\n<\/ol>\n

              Question 2.
              \nDescribe the role of microbes in agriculture and industries.
              \nAnswer:
              \nMicrobes in Agriculture :
              \nMicrobes play an important role in agricultrue as biocontrol agents and biofertilizers.
              \n(i) Biocontrol agents :
              \nMicroorganisms used for controlling harmful or pathogenic organisms and pests of plants are called as biocontrol agents Biopesticides.
              \n(E.g) Bacillus Thuringiensis.(Bt) is a species of bacteria that produces a protein called as ‘cry’ protein.<\/p>\n

              (ii) Biofertilizers:<\/p>\n

                \n
              • Microorganisms which enrich the soil with nutrients are called as biofertilizers.<\/li>\n
              • Bacteria, cyanobacteria and fungi are the main sources of biofertilizers .<\/li>\n
              • Atomspheric nitrogen has to be converted to available form of nitrogen.
                \nExample: Azotobacter, Nostoc (free living), Symbiotic microbes like Rhizobium, Frankia.<\/li>\n<\/ul>\n

                Microbes in Industries
                \nMicroorganisms play an important role in the production of wide variety of valuable products for the welfare of human beings.<\/p>\n

                Production of fermented beverages: Beverages like wine are produced by fermentation of grape fruits by Saccharomyces cerevisiae.<\/p>\n

                Curing of coffee beans, tea leaves and tobacco leaves : Beans of coffee and cocoa, leaves of tea and tobacco are fermented by the bacteria Bacillus megaterium. This gives the special aroma.<\/p>\n

                Production of curd : Lactobacillus sp. converts milk to curd.<\/p>\n

                Production of organic acids, enzymes and vitamins : Oxalic acid, acetic acid and citric acid are produced by fungus Aspergillus niger. Enzymes like lipases, invertase, proteases, and glucose oxidase are derived from microbes. Yeasts are rich source of vitamin-B complex.<\/p>\n

                \"Samacheer<\/p>\n

                Question 3.
                \nExplain the various types of viruses with examples.
                \nAnswer:
                \nViruses are categorised as :
                \n1. Plant virus : Virus that infect plants.
                \nE.g. Tobacco mosaic vims, Potato vims, Cauliflower mosaic virus.
                \n\"Samacheer<\/p>\n

                2. Animal virus : Vims that infect animals.
                \nE.g. Adenovims, Retrovims (HIV), Influenza vims, Polio vims.
                \n\"Samacheer<\/p>\n

                3. Bacteriophages : Vims that infect bacterial cells.
                \nE.g.T4 bacteriophage.
                \n\"Samacheer<\/p>\n

                \"Samacheer<\/p>\n

                Question 4.
                \nSuggest the immunization schedule for a new born baby till 12 months of age. Why it is necessary to follow the schedule?
                \nAnswer:
                \nThe immunization schedule must be followed so that the vaccines administered will protect the children in the future from infectious and life-threatening diseases.<\/p>\n

                Immunization Schedule for Children
                \n\"Samacheer<\/p>\n

                X. Assertion and Reason :<\/span><\/p>\n

                Mark the correct statement as:
                \n(a) If both A and R are true and R is correct explanation of A.
                \n(b) If both A and R are true but R is not the correct explanation of A.
                \n(c) If A is true but R is false.
                \n(d) If both A and R are false.<\/p>\n

                Question 1.
                \nAssertion : Chicken pox is a disease indicated by scars and marks in the body.
                \nReason : Chicken pox cenlses rashes on face and further spreads throughout the body.
                \nAnswer:
                \n(a) Both A and R are true and R is correct explanation of A<\/p>\n

                \"Samacheer<\/p>\n

                Question 2.
                \nAssertion: Dengue can be treated by intake of antibiotics.
                \nReason : Antibiotics blocks the multiplication of viruses.
                \nAnswer:
                \n(d) Both A and R are false<\/p>\n

                XI. Higher Order Thinking Skills :<\/span><\/p>\n

                Question 1.
                \nSuggest precautionary measures you can take in your school to reduce the incidence of infectious disease.
                \nAnswer:<\/p>\n

                  \n
                • Clean and hygienic environment should be maintained inside and outside the school.<\/li>\n
                • Enough first aid medicines should be kept in the school.<\/li>\n
                • Proper awareness about healthy diet and health instructions should be instructed to the students.<\/li>\n
                • If a student is identified with disease, it must be properly communicated to the students and nearby health authorities.<\/li>\n
                • The infected student \/ person must be kept away from other students in order to avoid the spread of infection.<\/li>\n<\/ul>\n

                  Question 2.
                  \nTejas suffered from typhoid while, Sachin suffered from tuberculosis. Which disease could have caused more damage and why?
                  \nAnswer:
                  \nTuberculosis is more dangerous than typhoid.
                  \nReason : Tuberculosis (TB) primarily affects lungs and also affect intestines, bones, and joints and other tissues of body. Severe cases may lead to death.<\/p>\n

                  \"Samacheer<\/p>\n

                  Intext Activities<\/strong><\/p>\n

                  ACTIVITY – 1<\/span><\/p>\n

                  Take the root nodules of any pulse or leguminous plant available in your locality. Wash it thoroughly with water. Crush the nodules on a clean glass slide. Add a drop of distilled water to the crushed material on the glass slide. Observe the preparation under compound microscope.<\/p>\n

                  Observation of Symbiotic microbes.<\/p>\n

                  Aim : To observe symbiotic bacteria shape on a clean glass plate.<\/p>\n

                  Materials Required :
                  \n1. Root nodules of leguminous plant, Clean glass slides, Water, Distilled water.<\/p>\n

                  Procedure :<\/p>\n

                    \n
                  1. Take the root nodules of the leguminous plant.<\/li>\n
                  2. Wash it thoroughly with water.<\/li>\n
                  3. Crush the nodules on a clean glass slide.<\/li>\n
                  4. Add a drop of distilled water to the crushed material on the glass slide.<\/li>\n<\/ol>\n

                    Observation:
                    \n\"\"<\/p>\n

                    Conclusion :
                    \nThe structure of symbiotic bacteria is observed in a clean glass plate.
                    \n[End of the activity]<\/p>\n

                    \"Samacheer<\/p>\n

                    ACTIVITY – 2<\/span><\/p>\n

                    Observe the mosquitoes that are active during the day time. Catch them using an insect net and observe their body and legs. What do you observe? Why are cases of Dengue reported in large numbers during post-monsoon season?<\/p>\n

                    Observation :
                    \nBody and legs of Aedes aegypti :
                    \nWe can find black and white stripes on the bodies and leg.
                    \nThe white marking in the leg is in the form of a lyre.<\/p>\n

                    High Dengue cases during post-monsoon<\/p>\n

                      \n
                    1. Due to the rainy season, conditions like stagnant water favours the mosquitoes to grow in large number.<\/li>\n
                    2. Thus, a sharp rise in dengue cases are reported. [End of the activity]<\/li>\n<\/ol>\n

                      \"Samacheer<\/p>\n

                      9th Science Guide World of Microbes Additional Important Questions and Answers<\/h3>\n

                      I. Choose the correct answer :<\/span><\/p>\n

                      Question 1.
                      \nWhich one of the following is a symbiotic bacteria?
                      \n(a) Azospirillum
                      \n(b) Azotobacter
                      \n(c) Rhizobium
                      \n(d) None of these
                      \nAnswer:
                      \n(c) Rhizobium<\/p>\n

                      Question 2.
                      \nThe shape of Vibrio cholerae is
                      \n(a) Spherical
                      \n(b) Spiral
                      \n(c) Rod
                      \n(d) None of these
                      \nAnswer:
                      \n(b) Spiral<\/p>\n

                      \"Samacheer<\/p>\n

                      Question 3.
                      \n……………are the site of protein synthesis in bacteria.
                      \n(a) Ribosomes
                      \n(b) Chromosomes
                      \n(c) Plasmid
                      \n(d) Nucleus
                      \nAnswer:
                      \n(a) Ribosomes<\/p>\n

                      Question 4.
                      \nFungi reproduce through …………..
                      \n(a) binary fission
                      \n(b) budding
                      \n(c) spore formation
                      \n(d) all of these
                      \nAnswer:
                      \n(d) all of these<\/p>\n

                      \"Samacheer<\/p>\n

                      Question 5.
                      \nWhich one of the following is not an antibiotic derived from Bacteria?
                      \n(a) Cephalosporin
                      \n(b) Erythromycin
                      \n(c) Bacitracin
                      \n(d) Streptomycin
                      \nAnswer:
                      \n(a) Cephalosporin<\/p>\n

                      Question 6.
                      \nAIDS is’ a …………… disease.
                      \n(a) Endemic
                      \n(b) Epidermic
                      \n(c) Pandemic
                      \n(d) Sporadic
                      \nAnswer:
                      \n(c) Pandemic<\/p>\n

                      \"Samacheer<\/p>\n

                      Question 7.
                      \nFever, sore throat, and choking of air passage are symptoms of ……………
                      \n(a) influenza
                      \n(b) diphtheria
                      \n(c) whooping cough
                      \n(d) typhoid
                      \nAnswer:
                      \n(a) influenza<\/p>\n

                      Question 8.
                      \nMyxovirus is the causative agent for …………… disease.
                      \n(a) common cold
                      \n(b) measles
                      \n(c) influenza
                      \n(d) diarrhoea
                      \nAnswer:
                      \n(c) influenza<\/p>\n

                      \"Samacheer<\/p>\n

                      Question 9.
                      \nThe symptoms of measles is ……………
                      \n(a) eruption of small rashes in skin
                      \n(b) redness of eye
                      \n(c) pneumonia
                      \n(d) all the above
                      \nAnswer:
                      \n(d) all the above<\/p>\n

                      Question 10.
                      \nThe stages of malarial parasite are developed in the …………… of mosquito
                      \n(a) respiratory tract
                      \n(b) gastrointestinal tract
                      \n(c) intestinal tract
                      \n(d) none of these
                      \nAnswer:
                      \n(b) gastrointestinal tract<\/p>\n

                      \"Samacheer<\/p>\n

                      Question 11.
                      \nIncubation period of the virus for chikungunya is usually . ……………
                      \n(a) 2-12 days
                      \n(b) 2-7 days
                      \n(c) 4-8 days
                      \n(d) 3-9 days
                      \nAnswer:
                      \n(a) 2-12 days<\/p>\n

                      \"Samacheer<\/p>\n

                      Question 12.
                      \nThe disease that displays Nocturnal periodicity ……………
                      \n(a) swine flu
                      \n(b) dengue
                      \n(c) filaria
                      \n(d) influenza
                      \nAnswer:
                      \n(c) filaria<\/p>\n

                      Question 13.
                      \nNasal spray vaccine can be administered to ……………patients.
                      \n(a) chikungunya
                      \n(b) dengue
                      \n(c) influenza
                      \n(d) swine flu
                      \nAnswer:
                      \n(d) swine flu<\/p>\n

                      Question 14.
                      \nHuman Immuno deficiency Virus (HIV) was first isolated by …………..
                      \n(a) Robert Koch
                      \n(b) Robert Gallo
                      \n(c) Ronald Ross
                      \n(d) Louis Pasteur
                      \nAnswer:
                      \n(b) Robert Gallo<\/p>\n

                      \"Samacheer<\/p>\n

                      Question 15.
                      \nThe disease that is eliminated totally by the vaccination process is …………….
                      \n(a) chicken pox
                      \n(b) Filaria
                      \n(c) smallpox
                      \n(d) None of these
                      \nAnswer:
                      \n(c) small pox<\/p>\n

                      Question 16.
                      \nAmong the following, which is belongs to water-borne diseases?
                      \n(a) Hepatitis A
                      \n(b) Hepatitis B
                      \n(c) Influenza
                      \n(d) Dengue
                      \nAnswer:
                      \n(a) Hepatitis A<\/p>\n

                      \"Samacheer<\/p>\n

                      Question 17.
                      \nMeasles vaccine can be administered to the child at the age of ……………
                      \n(a) 18-24 months
                      \n(b) 15-18 months
                      \n(c) 9-12 months
                      \n(d) 14th week
                      \nAnswer:
                      \n(c) 9 – 12 months<\/p>\n

                      Question 18.
                      \nMycology is the branch of biology that deals with the study of ……………
                      \n(a) algae
                      \n(b) virus
                      \n(c) bacteria
                      \n(d) fungi
                      \nAnswer:
                      \n(d) fungi<\/p>\n

                      Question 19.
                      \nThe major constituent of vinegar is ……………
                      \n(a) citric acid
                      \n(b) acetic acid
                      \n(c) oxalic acid
                      \n(d) hydrochloric acid
                      \nAnswer:
                      \n(b) acetic acid<\/p>\n

                      \"Samacheer<\/p>\n

                      Question 20.
                      \nBacteria involved in curd formation is ……………
                      \n(a) Lactobacillus acidophilus
                      \n(b) Nitrosomonas
                      \n(c) Bacillus ramous
                      \n(d) none of the above
                      \nAnswer:
                      \n(a) Lactobacillus acidophilus<\/p>\n

                      Question 21.
                      \nThe most fetal form of malaria is caused by ……………..
                      \n(a) Plasmodium ovale
                      \n(b) Plasmodium falciparum
                      \n(c) Plasmodium malariae
                      \n(d) Plasmodium vivax
                      \nAnswer:
                      \n(b) Plasmodium falciparum<\/p>\n

                      Question 22.
                      \nSyphilis is caused by ………………….
                      \n(a) Treponema pallidum
                      \n(b) Leptospira
                      \n(c) Pasteurella
                      \n(d) Vibrio cholerae
                      \nAnswer:
                      \n(a) Treponema pallidum<\/p>\n

                      \"Samacheer<\/p>\n

                      Question 23.
                      \nMosquito-borne viral diseases are …………………
                      \n(a) malaria and yellow fever
                      \n(b) dengue and chikungunya
                      \n(c) filariasis and typhus
                      \n(d) kala-azar and diphtheria
                      \nAnswer:
                      \n(b) dengue and chikungunya<\/p>\n

                      Question 24.
                      \nWhich one of the following is a pair of viral disease?
                      \n(a) Filariasis, AIDS
                      \n(b) Common cold, AIDS
                      \n(c) Dysentery, Common cold
                      \n(d) Typhoid, Tuberculosis
                      \nAnswer:
                      \n(b) Common cold, AIDS<\/p>\n

                      \"Samacheer<\/p>\n

                      Question 25.
                      \nWhich of the following disease is spread by animal bite?
                      \n(a) Pneumonia
                      \n(b) Tuberculosis
                      \n(c) Cholera
                      \n(d) Rabies
                      \nAnswer:
                      \n(d) Rabies<\/p>\n

                      II. Fill in the blanks :<\/span><\/p>\n

                      1. Bacterial cell was covered by a strong cell wall made up of ……………
                      \nAnswer:
                      \npeptidoglycan<\/p>\n

                      2. In bacteria, a small extra chromosomal circular DNA called ………….. is found in the cytoplasm.
                      \nAnswer:
                      \nplasmid<\/p>\n

                      \"Samacheer<\/p>\n

                      3. ………………bacteria live on dead organic matter.
                      \nAnswer:
                      \nSaprophytic<\/p>\n

                      4. Viruses are non-cellular, …………………… parasites.
                      \nAnswer:
                      \nself-replicating<\/p>\n

                      5. Adenovirus is………………….virus.
                      \nAnswer:
                      \nanimal<\/p>\n

                      \"Samacheer<\/p>\n

                      6. The cell wall of fungi is made up of ……………… and …………….
                      \nAnswer:
                      \ncellulose, hemicellulose<\/p>\n

                      7. Prions do not contain …………………..
                      \nAnswer:
                      \nNucleic acid<\/p>\n

                      8. \u2018Cry\u2019 protein is produced by the bacteria………………….
                      \nAnswer:
                      \nBacillus Thuringiensis<\/p>\n

                      9. Yeasts are rich source of …………………..
                      \nAnswer:
                      \nvitamin – B complex<\/p>\n

                      \"Samacheer<\/p>\n

                      10. Vaccines stimulate the body to produce …………………. against the …………………. in the microbes.
                      \nAnswer:
                      \nantibodies, antigen<\/p>\n

                      11. Cholera is a ………… disease
                      \nAnswer:<\/p>\n

                      12. The interval between infection and first appearance of the diseases is called …………………..period.
                      \nAnswer:
                      \nincubation<\/p>\n

                      13. …………. is the Father of Bacteriology
                      \nAnswer:
                      \nRobert Koch<\/p>\n

                      14. The causative agent (bacteria) of whooping cough is ………….
                      \nAnswer:
                      \nBordetalla pertussis<\/p>\n

                      \"Samacheer<\/p>\n

                      15. Inflammation of nasal mucosa and pharynx are the symptoms of ………….
                      \nAnswer:
                      \ninfluenza<\/p>\n

                      16. The most vulnerable age of polio is between ………… years
                      \nAnswer:
                      \n3 – 6<\/p>\n

                      17. Use of ………… drugs kills the stages of malaria parasite.
                      \nAnswer:
                      \nQuinine<\/p>\n

                      \"Samacheer<\/p>\n

                      18. Dengue is known as ………… fever.
                      \nAnswer:
                      \nBreak bone<\/p>\n

                      19. Nilavembu kudineer is known to increase…………
                      \nAnswer:
                      \nblood platelet count<\/p>\n

                      20. The process of vaccination was introduced by ……………….
                      \nAnswer:
                      \nEdward Jenner<\/p>\n

                      \"Samacheer<\/p>\n

                      21. The hyphae with branches form a complex network called ……………
                      \nAnswer:
                      \nmycelium<\/p>\n

                      22. First antibiotic …………… was developed by ……………
                      \nAnswer:
                      \npenicillin, Alexander Fleming<\/p>\n

                      23. Baker’s yeast is …………….
                      \nAnswer:
                      \nthe yeast used in baking bread<\/p>\n

                      24. The two non-symbiotic nitrogen fixing bacteria are ……………and ……………
                      \nAnswer:
                      \ncyanobacteria, Azotobacter<\/p>\n

                      III. Match the following :<\/span><\/p>\n

                      I.<\/p>\n\n\n\n\n\n\n
                      1. World Anti-Tuberculosis day<\/td>\na) 7th April<\/td>\n<\/tr>\n
                      2. World Malaria day<\/td>\nb) 1st December<\/td>\n<\/tr>\n
                      3. World Health day<\/td>\nc) 24th March<\/td>\n<\/tr>\n
                      4. World AIDS day<\/td>\nd) 25th April<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                      Answer:
                      \n1 – c, 2 – d, 3 – a, 4 – b II.<\/p>\n

                      \"Samacheer<\/p>\n

                      II.<\/p>\n\n\n\n\n\n\n
                      1. Rhizobium<\/td>\na) Phosphorus<\/td>\n<\/tr>\n
                      2. Azotobacter<\/td>\nb) Soil bacterium<\/td>\n<\/tr>\n
                      3. Mycorrhizae<\/td>\nc) Anabaena<\/td>\n<\/tr>\n
                      4. Azolla<\/td>\nd) Antifungal compounds<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                      Answer:
                      \n1 – b, 2 – d, 3 – a, 4 – c<\/p>\n

                      III.<\/p>\n\n\n\n\n\n\n
                      1. Saccharomyces cerevisiae<\/td>\na) Biofertilizers<\/td>\n<\/tr>\n
                      2. Mycorrhizae<\/td>\nb) Organic acids<\/td>\n<\/tr>\n
                      3. Aspergillus Niger<\/td>\nc) Fermented beverages<\/td>\n<\/tr>\n
                      4. Bacillus Megaterium<\/td>\nd) Curing of tobacco leaves<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                      Answer:
                      \n1 – c, 2 – a, 3 – b, 4- d<\/p>\n

                      IV.<\/p>\n\n\n\n\n\n\n\n
                      Diseases<\/td>\nIncubation Period<\/td>\n<\/tr>\n
                      1. Dengue<\/td>\na) 2-12 days<\/td>\n<\/tr>\n
                      2. Chikungunya<\/td>\nb) 5-6 days<\/td>\n<\/tr>\n
                      3. Filaria<\/td>\nc) 4 2-7 days<\/td>\n<\/tr>\n
                      4. Avian Influenza<\/td>\nd) 8-16 months<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                      Answer:
                      \n1 – b, 2 – a, 3 – d, 4- c<\/p>\n

                      \"Samacheer<\/p>\n

                      V.
                      \n\"Samacheer
                      \nAnswer:
                      \n\"Samacheer<\/p>\n

                      IV. State whether True or False. If false write the correct statement<\/span><\/p>\n

                      1. Virions are the smallest among the infective agents.
                      \nAnswer:
                      \nTrue.<\/p>\n

                      2. Viruses are devoid of cellular organelles like ribosomes^ mitochondria, etc.
                      \nAnswer:
                      \nTrue.<\/p>\n

                      3. Prions are found in neurons and are cone-shaped.
                      \nAnswer:
                      \nFalse.
                      \nCorrect statement: Prions are found in neurons and are rod-shaped.<\/p>\n

                      \"Samacheer<\/p>\n

                      4. In human beings, antibodies are used to cure infectious diseases like cholera, typhoid, etc.
                      \nAnswer:
                      \nFalse.
                      \nCorrect statement: In human beings, antibodies are used to control infectious diseases like cholera, typhoid, etc.<\/p>\n

                      5. An infection develops when these pathogens enter the human body.
                      \nAnswer:
                      \nTrue.<\/p>\n

                      6. Airborne diseases are caused by fungi.
                      \nAnswer:
                      \nFalse.
                      \nCorrect statement: Airborne diseases are caused by bacteria and viruses.<\/p>\n

                      7. Influenza commonly occurs during adult age.
                      \nAnswer:
                      \nFalse.
                      \nCorrect statement: Influenza commonly occurs during childhood.<\/p>\n

                      \"Samacheer<\/p>\n

                      8. Malaria is caused by the fungal parasite plasmodium.
                      \nAnswer:
                      \nFalse.
                      \nCorrect statement: Malaria is caused by the protozoan parasite Plasmodium.<\/p>\n

                      9. Filaria is transmitted by the bite of an infected Culex mosquito.
                      \nAnswer:
                      \nTrue.<\/p>\n

                      10. Swine flu spreads through the air by an acute respiratory virus.
                      \nAnswer:
                      \nTrue.<\/p>\n

                      11. Hepatitis A causes cirrhosis of the liver.
                      \nAnswer:
                      \nFalse.
                      \nCorrect statement: Hepatitis B causes cirrhosis of the liver.<\/p>\n

                      \"Samacheer<\/p>\n

                      12. Oral polio vaccine is a killed vaccine.
                      \nAnswer:
                      \nFalse
                      \nCorrect statement: Oral polio vaccine is a Live vaccine.<\/p>\n

                      13. Glycogen and oil globules are stored forms of food in fungi.
                      \nAnswer:
                      \nTrue.<\/p>\n

                      14. One of the differences between virus and viroid is the presence of protein coat in viroid and its absence in the virus.
                      \nAnswer:
                      \nFalse.
                      \nCorrect statement: One of the differences between virus and viroid is the presence of protein coat in vim:: and its absence in viroid.<\/p>\n

                      \"Samacheer<\/p>\n

                      V. Assertion and Reason :<\/span><\/p>\n

                      Mark the correct answer :
                      \n(a) If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
                      \n(b) If both Assertion and Reason are true but the reason is not the correct explanation of assertion.
                      \n(c) If Assertion is true but Reason is false.
                      \n(d) If Assertion is false but Reason is true.<\/p>\n

                      Question 1.
                      \nAssertion: Some bacteria may be non-motile.
                      \nReason: Bacteria have a special structure called flagella which are found on cell surfaces.
                      \nAnswer:
                      \n(d) Assertion is false but Reason is true<\/p>\n

                      Question 2.
                      \nAssertion : Bacillus Thuringiensis is a biocontrol agent.
                      \nReason : It produces a protein called ‘cry protein’ which kills insect larva.
                      \nAnswer:
                      \n(a) Both assertion and reason are true and Reason is the correct explanation of Assertion<\/p>\n

                      \"Samacheer<\/p>\n

                      Question 3.
                      \nAssertion : Cancer is a non-infectious disease.
                      \nReason : Cancer is caused by external factors like pathogens invading the body.
                      \nAnswer:
                      \n(c) Assertion is true but Reason is false
                      \nReason : Cancer is caused by internal factors like the malfunctioning of organs.<\/p>\n

                      Question 4.
                      \nAssertion : An infection develops when pathogens enter the human body.
                      \nPathogen enters the human body through contaminated air, water, food, soil, physical contact etc.
                      \nAnswer:
                      \n(a) Both assertion and reason are true and Reason is the correct explanation of Assertion<\/p>\n

                      Question 5.
                      \nAssertion : Chikungunya is transmitted in humans by the bite of infected Aedes aegypti mosquito during the day time.
                      \nReason : Chikungunya is caused by Rotavirus.
                      \nAnswer:
                      \n(c) Assertion is true but Reason is false]
                      \nReason : Chikungunya is caused by a single-stranded RNA virus.<\/p>\n

                      \"Samacheer<\/p>\n

                      VI. Expand the following :<\/span><\/p>\n

                        \n
                      1. CJD<\/li>\n
                      2. TT<\/li>\n
                      3. OPV<\/li>\n
                      4. HAY<\/li>\n
                      5. AIDS<\/li>\n
                      6. MMR<\/li>\n<\/ol>\n

                        Answer:<\/p>\n

                          \n
                        1. CJD – Creutzfeldt -Jakob Disease<\/li>\n
                        2. TT – Tetanus Toxoid<\/li>\n
                        3. OPV – Oral Polio Vaccine<\/li>\n
                        4. HAV – Hepatitis A Virus<\/li>\n
                        5. AIDS – Acquired Immuno Deficiency Syndrome<\/li>\n
                        6. MMR – Mumps, Measles, Rubella<\/li>\n<\/ol>\n

                          \"Samacheer<\/p>\n

                          VII. Define the following :<\/span><\/p>\n

                          1. Disease, 2. Infection, 3. Antibiotics, 4. Toxin, 5. Vector
                          \nAnswer:
                          \n1. Disease:
                          \nThe disease can be defined as an impairment or malfunctioning of the normal state of the living organism that disturbs or modifies the performance of vital functions of the body.<\/p>\n

                          2. Infection:
                          \nInfection is the entry, development, or multiplication of an infectious agent in the human body or animals.<\/p>\n

                          3. Antibiotics:
                          \nAntibiotics are metabolic products of microorganisms whose very low concentrations are inhibitory or detrimental to other microbes.<\/p>\n

                          4. Toxin :
                          \nThe poisonous substances secreted by pathogens that cause diseases are called toxins.<\/p>\n

                          5. Vector:
                          \nVector is an agent that acts as an intermediate carrier of the pathogen.<\/p>\n

                          \"Samacheer<\/p>\n

                          VIII. Answer in one or two sentences :<\/span><\/p>\n

                          Question 1.
                          \nWhat is bacteria?
                          \nAnswer:
                          \nBacteria are microscopic, single-celled prokaryotic organisms without a nucleus and other cell organelles. ><\/p>\n

                          Question 2.
                          \nDifferentiate Parasites and Saprophytes.
                          \nAnswer:
                          \nParasites :
                          \nFungi living on living hosts.<\/p>\n

                          Saprophytes :
                          \nFungi living on dead organic matter.<\/p>\n

                          \"Samacheer<\/p>\n

                          Question 3.
                          \nWhat is the incubation period?
                          \nAnswer:
                          \n1. The interval between infection and the first appearance of the diseases is called the incubation period.
                          \n2. It may vary from few hours to several days.<\/p>\n

                          Question 4.
                          \nDifferentiate Exotoxins and Endotoxins.
                          \nAnswer:
                          \nExotoxins :
                          \nThere are directly secreted by the pathogens.<\/p>\n

                          Endotoxins :
                          \nThere are released by the disintegration of pathogens.<\/p>\n

                          Question 5.
                          \nWhy is dengue also known as break-bone fever?
                          \nAnswer:
                          \nThe name break bone fever was given because contortions caused intense joint and muscle pain.<\/p>\n

                          \"Samacheer<\/p>\n

                          Question 6.
                          \nWhat is an immunization?
                          \nAnswer:
                          \nImmunization is a process of developing resistance to infections by administration of antigens (or) antibodies. .<\/p>\n

                          Question 7.
                          \nWhat is TAB?
                          \nAnswer:
                          \nTAB is a combined vaccine for Typhoid, Paratyphi A and Paratyphi B.<\/p>\n

                          Question 8.
                          \nName two diseases transmitted by Aedes aegypti mosquito?
                          \nAnswer:<\/p>\n

                            \n
                          1. Chikungunya,<\/li>\n
                          2. Dengue.<\/li>\n<\/ol>\n

                            Question 9.
                            \nWhat is known as reservior of infection? Give two example.
                            \nAnswer:
                            \nReservoir of infection are breeding ground for pathogens. E.g. Water, soil.<\/p>\n

                            \"Samacheer<\/p>\n

                            Question 10.
                            \nDifferentiate signs and symptoms of disease.
                            \nAnswer:
                            \nSigns :
                            \nSigns of disease provide information about particular disease.<\/p>\n

                            Symptoms :
                            \nSymptoms are recognizable signs of infectious disease.<\/p>\n

                            Question 11.
                            \nName one disease that is transmitted by houseflies. Mention their causative pathogen.
                            \nAnswer:
                            \nCholera – Vibrio cholerae (pathogen)<\/p>\n

                            Question 12.
                            \nName the scientist who first discovered penicillin antibiotic. Can you name any other known antibiotic?
                            \nAnswer:<\/p>\n

                              \n
                            1. Penicillin was discovered by Alexander Fleming.<\/li>\n
                            2. Other known Antibiotic – Tetracycline.<\/li>\n<\/ol>\n

                              \"Samacheer<\/p>\n

                              Question 13.
                              \nA baby is suffering from diarrhoea, while other babies in the same locality do not.
                              \nMention the possible causes that you think. What would be the possible solutions for this? \u00bb
                              \nAnswer:<\/p>\n

                                \n
                              1. Cause for Diarrhoea: Contaminated food (or) water.<\/li>\n
                              2. Possible solutions: Hygienic sanitary condition, Use of Oral Rehydration Solution (ORS).<\/li>\n<\/ol>\n

                                Question 14.
                                \nSanjay had an attack of chickenpox and has just recovered. The health officer of his locality says that the disease would not occur again for him. What would be the reason for this?
                                \nAnswer:
                                \nWhile Chicken Pox attacks the first time, it develops immunity for the rest of life.<\/p>\n

                                IX. Short answer questions :<\/span><\/p>\n

                                Question 1.
                                \nBriefly explain the reproduction of fungi using a flow chart.
                                \nAnswer:
                                \n\"Samacheer<\/p>\n

                                \"Samacheer<\/p>\n

                                Question 2.
                                \nWhat is an epidemic disease?
                                \nAnswer:
                                \nEpidemic disease is a disease that breaks out and affects large number of people in a particular geographical region and spreads at the same time. E.g. Influenza.<\/p>\n

                                Question 3.
                                \nDifferentiate between Infectious and Non-Infectious disease.
                                \nAnswer:
                                \nInfections Disease<\/p>\n

                                  \n
                                1. They are communicable diseases. .<\/li>\n
                                2. They are caused by external factors. Invading of pathogens such as bacteria, virus, vectors, parasites etc.
                                  \nE.g. Cholera, Malaria, Chickenpox.<\/li>\n<\/ol>\n

                                  Non-infectious disease<\/p>\n

                                    \n
                                  1. They are non-communicable diseases<\/li>\n
                                  2. They are caused by internal factors.\n
                                      \n
                                    • Malfunctioning of organs,<\/li>\n
                                    • Genetic causes,<\/li>\n
                                    • Hormonal imbalance and<\/li>\n
                                    • Defective Immune system
                                      \nE.g. Cancer, Diabetes.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n

                                      \"Samacheer<\/p>\n

                                      Question 4.
                                      \nWhat causes illness?
                                      \nAnswer:
                                      \nAn illness is casual due to a specific infectious agent, capable of being directly or indirectly transmit infection from person to person, animal to animal or from the environment (air, water & food) and insects.<\/p>\n

                                      Question 5.
                                      \nHow are respiratory tract infections acquired?
                                      \nAnswer:
                                      \nRespiratory tract infections are acquired by inhaling air containing the pathogen that is transmitted through droplets caused by cough (or) sneeze, dust, spores, etc.<\/p>\n

                                      Question 6.
                                      \nName the different species of protozoa plasmodium.
                                      \nAnswer:
                                      \nThe different species of plasmodium are –<\/p>\n

                                        \n
                                      1. Plasmodium vivax<\/li>\n
                                      2. Plasmodium malariae<\/li>\n
                                      3. Plasmodium falciparum<\/li>\n
                                      4. Plasmodium ovale.<\/li>\n<\/ol>\n

                                        \"Samacheer<\/p>\n

                                        Question 7.
                                        \nList the precautionary measures to avoid Avian Influenza.
                                        \nAnswer:
                                        \nPrevention and Control:<\/p>\n

                                          \n
                                        • Avoid open-air markets where infected birds are sold.<\/li>\n
                                        • Avoid contact and consumption of infected birds.<\/li>\n
                                        • Proper cleaning and cooking of poultry.<\/li>\n<\/ul>\n

                                          Question 8.
                                          \nMention the symptoms of poliomyelitis.
                                          \nAnswer:
                                          \nSymptoms of poliomyelitis :<\/p>\n

                                            \n
                                          • Paralysis of limbs and muscles.<\/li>\n
                                          • Difficulty in walking.<\/li>\n<\/ul>\n

                                            Question 9.
                                            \nWhen Malar, who is suffering from high fever, muscle, and joint pain, undergoes a blood test, it was found that her blood platelet was decreased.
                                            \na. What disease is Malar infected with?
                                            \nb. How is the disease transmitted?
                                            \nc. How can it be treated?
                                            \nAnswer:
                                            \na. Dengue fever.
                                            \nb. Dengue was caused by a virus which is transmitted by the Aedes aegypti mosquito.
                                            \nc. Treatment:<\/p>\n

                                              \n
                                            • Administer paracetamol to reduce fever and body ache.<\/li>\n
                                            • Increase intake of fluid to increase immunity.<\/li>\n
                                            • Complete rest for rehabilitation.<\/li>\n<\/ul>\n

                                              \"Samacheer<\/p>\n

                                              Question 10.
                                              \nHow is typhoid prevented and treated?
                                              \nAnswer:
                                              \nPrevention:<\/p>\n

                                                \n
                                              • Contaminated food by flies-and dust should be prevented.<\/li>\n
                                              • Basic sanitation and hygienic practices should be improved.<\/li>\n<\/ul>\n

                                                Treatment:
                                                \nTyphoid should be treated with antibiotic drugs.<\/p>\n

                                                Question 11.
                                                \nWe are advised to take bland and nutritious food when we are sick. What is the reason?
                                                \nAnswer:<\/p>\n

                                                  \n
                                                • Bland and nutritious food are soft, less spicy and low in fibre.<\/li>\n
                                                • They are easy digestable and energy giving food. . . .
                                                  \nThus, sick person can restore his immunity through bland and nutritious food.<\/li>\n<\/ul>\n

                                                  Question 12.
                                                  \nHow will you differentiate Hepatitis A from Hepatitis B?
                                                  \nAnswer:<\/p>\n\n\n\n\n\n\n
                                                  Hepatitis A<\/td>\nHepatitis B<\/td>\n<\/tr>\n
                                                  1. Caused by Hepatitis A virus (HAV)<\/td>\n1. Caused by Hepatitis B virus<\/td>\n<\/tr>\n
                                                  2. Transmitted through<\/p>\n
                                                    \n
                                                  1. Contaminated water<\/li>\n
                                                  2. Food<\/li>\n
                                                  3. Oral route<\/li>\n<\/ol>\n<\/td>\n
                                                  		2. Transmitted through contact (from infected person to a healthy person)<\/p>\n
                                                    \n
                                                  1. Sexual.<\/li>\n
                                                  2. Blood contact.<\/li>\n
                                                  3. By surgical equipment (infected needles and syringes).<\/li>\n
                                                  4. Material (foetal transmission from infected mother to the foetus).<\/li>\n<\/ol>\n<\/td>\n<\/tr>\n
                                                  3. Liver is affected in Jaundice (Yellow fever)<\/td>\n3. Cirrhosis of liver.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                                                  \"Samacheer<\/p>\n

                                                  X. Long Answer question :\u00a0<\/span><\/p>\n

                                                  Question 1.
                                                  \nEnumerate the living and non-living characters of virus.
                                                  \nAnswer:
                                                  \n1. Living characters of viruses:<\/p>\n

                                                    \n
                                                  • They have nucleic acid DNA or RNA i.e., the genetic material that can replicate.<\/li>\n
                                                  • They can multiply in the living cells of the host.<\/li>\n
                                                  • They can attack specific hosts.<\/li>\n<\/ul>\n

                                                    2. Non-living characters of viruses:<\/p>\n

                                                      \n
                                                    • Viruses remain as inert material outside their hosts.<\/li>\n
                                                    • They are devoid of the cell membrane and cell wall.<\/li>\n
                                                    • They are devoid of cellular organelles like ribosomes, mitochondria, etc.<\/li>\n
                                                    • They can be crystallised.<\/li>\n<\/ul>\n

                                                      Question 2.
                                                      \nDiscuss how diseases are categorised.
                                                      \nAnswer:
                                                      \nDisease can be catagorized on the basis of:<\/p>\n

                                                      (i) Extent of occurrence
                                                      \n(ii) Infectious nature
                                                      \n(iii) Type of pathogen
                                                      \n(iv) Transmitting Agent<\/p>\n

                                                      (i) Extent of occurrence :<\/p>\n

                                                        \n
                                                      • Endemic diseases – Found in the certain geographical area affects the fewer number of people, E.g. Goitre in sub = Himalayan region.<\/li>\n
                                                      • Epidemic diseases – Disease which breaks out and affects a large number of people in a particular geographical region and spreads at the same time. E.g. Influenza.<\/li>\n
                                                      • Pandemic disease – Widely distributed on a global scale. E.g. AIDS.<\/li>\n
                                                      • Sporadic disease – Occasional occurrence of a disease. E.g. Cholera and malaria.<\/li>\n<\/ul>\n

                                                        (ii) Infectious nature:<\/p>\n

                                                        1. Infectious disease are communicable diseases. Caused by external factors pathogenic organisms. E.g. Chickenpox and malaria.<\/p>\n

                                                        2. Non-Infectious disease:<\/p>\n

                                                          \n
                                                        • Non-communicable diseases.<\/li>\n
                                                        • Caused by internal factors like :<\/li>\n
                                                        • Malfunctioning of organs and genetic causes. Hormonal imbalance and immune system defect. E.g. Diabetes, coronary heart diseases, obesity, cancer, goitre etc.<\/li>\n<\/ul>\n

                                                          (iii) Types of pathogen :<\/p>\n

                                                            \n
                                                          • Bacterial diseases<\/li>\n
                                                          • Viral diseases<\/li>\n
                                                          • Fungal diseases<\/li>\n
                                                          • Protozoan diseases<\/li>\n<\/ul>\n

                                                            (iv) Transmitting agent:<\/p>\n

                                                              \n
                                                            • Airborne diseases: Due to continuous inhalation of contaminated air.
                                                              \nE.g. Tuberculosis.<\/li>\n
                                                            • Waterborne diseases: Microbes present in the contaminated water cause various infectious diseases.
                                                              \nE.g. Cholera, typhoid, etc.<\/li>\n
                                                            • Vector-borne diseases: Vector is an agent that acts as an intermediate carrier of the pathogen.
                                                              \nE.g. Malaria, filaria, chikungunya.<\/li>\n<\/ul>\n

                                                              \"Samacheer<\/p>\n

                                                              Question 3.
                                                              \nDiscuss the strategies to adopt to prevent diseases transmitted through mosquitoes.
                                                              \nAnswer:<\/p>\n

                                                                \n
                                                              • Prevention of mosquito bites by using mosquito nets mosquito screens, mosquito repellents, and ointments.<\/li>\n
                                                              • Providing adequate sanitation, underground wastewater disposable system, and drainage of stagnant water to eliminate the breeding places.<\/li>\n
                                                              • Avoid the collection of water in any uncovered container such as water tanks, pots, flowers, discarded tyres, etc.<\/li>\n
                                                              • Spraying oil on stagnated water bodies to control mosquito larvae.<\/li>\n
                                                              • Adult mosquitoes can be killed by spraying insecticides.<\/li>\n
                                                              • Application of citronella oil (or) eucalyptus oil on the exposed skin.<\/li>\n<\/ul>\n

                                                                Question 4.
                                                                \nAmal, a thirteen-year-old boy is suffering from fever, headache, body pain, vomiting, and diarrhoea. He finds it difficult to breathe.<\/p>\n

                                                                  \n
                                                                1. Diagnose the disease.<\/li>\n
                                                                2. What is the causative agent?<\/li>\n
                                                                3. What prevention and control measures can be taken?<\/li>\n<\/ol>\n

                                                                  Answer:<\/p>\n

                                                                    \n
                                                                  1. Diagnosed Disease: Swine flu.<\/li>\n
                                                                  2. Causative agent: InfluerKa virus H1N1<\/li>\n
                                                                  3. Prevention and control:\n
                                                                      \n
                                                                    • Administration of nasal spray vaccine.<\/li>\n
                                                                    • Avoiding close contact with a person suffering from the flu.<\/li>\n
                                                                    • Intake of water and fruit juices will help prevent dehydration.<\/li>\n
                                                                    • Plenty of rest will help the body fight infection.<\/li>\n
                                                                    • Always wash hands regularly and practice good hygiene.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n

                                                                      Question 5.
                                                                      \nName the causative agent of typhoid in humans. How does the pathogen gain entry into the human body? Write the diagnostic symptoms and mention the organ that is affected in severe cases.
                                                                      \nAnswer:<\/p>\n

                                                                        \n
                                                                      • Causative agent of typhoid: Salmonella Typhi (Bacteria)<\/li>\n
                                                                      • The entry of Pathogen: Food and water contaminated by the faeces of an infected person through houseflies.<\/li>\n
                                                                      • Diagnostic symptoms: Fever, weakness, and vomiting.<\/li>\n
                                                                      • Affected organ: Small Intestine.<\/li>\n<\/ul>\n

                                                                        \"Samacheer<\/p>\n

                                                                        Question 6.
                                                                        \nSome human diseases are transmitted only when the blood of a patient comes in close contact with the blood of a healthy person. In one such disease, there is a progressive decrease in WBC of the patient.<\/p>\n

                                                                          \n
                                                                        1. Name the disease and its causative agent.<\/li>\n
                                                                        2. Name the type of WBC affected during infection.<\/li>\n
                                                                        3. How does the blood of a patient come in contact with the blood of a healthy patient?<\/li>\n
                                                                        4. Suggest three methods that help in preventing such infection.<\/li>\n<\/ol>\n

                                                                          Answer:<\/p>\n

                                                                            \n
                                                                          1. Disease Name Causative agent: AIDS (Acquired Immuno Deficiency Syndrome).<\/li>\n
                                                                          2. Affected WBC type: Human Immunodeficiency Virus (HIV)<\/li>\n
                                                                          3. Contact of blood: Lymphocytes (T-lymphocytes)<\/li>\n
                                                                          4. Prevention methods: Transfusion of unscreened blood (blood contact).\n
                                                                              \n
                                                                            • Usage of disposable syringes and needles.<\/li>\n
                                                                            • Screening of blood before blood transfusion.<\/li>\n
                                                                            • Avoid sharing shaving blades\/razors.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n
                                                                                \n
                                                                              • <\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"

                                                                                Tamilnadu State Board New Syllabus Samacheer Kalvi 9th Science Guide Pdf Chapter 22 World of Microbes Text Book Back Questions and Answers, Notes. Tamilnadu Samacheer Kalvi 9th Science Solutions Chapter 22 World of Microbes 9th Science Guide World of Microbes Text Book Back Questions and Answers I. Choose the correct answer : Question 1. Which …<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":""},"categories":[3],"tags":[],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/samacheer-kalvi.com\/wp-json\/wp\/v2\/posts\/24230"}],"collection":[{"href":"https:\/\/samacheer-kalvi.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/samacheer-kalvi.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/samacheer-kalvi.com\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/samacheer-kalvi.com\/wp-json\/wp\/v2\/comments?post=24230"}],"version-history":[{"count":1,"href":"https:\/\/samacheer-kalvi.com\/wp-json\/wp\/v2\/posts\/24230\/revisions"}],"predecessor-version":[{"id":47990,"href":"https:\/\/samacheer-kalvi.com\/wp-json\/wp\/v2\/posts\/24230\/revisions\/47990"}],"wp:attachment":[{"href":"https:\/\/samacheer-kalvi.com\/wp-json\/wp\/v2\/media?parent=24230"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/samacheer-kalvi.com\/wp-json\/wp\/v2\/categories?post=24230"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/samacheer-kalvi.com\/wp-json\/wp\/v2\/tags?post=24230"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}