2.3 ADDITIONAL QUESTIONS AND ANSWERS:
1:.Match the organisms in Column I with their action in Column II.
| Column I | Column II |
| (a) Bacteria (b) Rhizobium (c) Lactobacillus (d) Yeast (e) A protozoan (f) A virus |
(i) Fixing nitrogen (ii) Setting of curd (iii) Baking of bread (iv) Causing malaria (v) Causing cholera (vi) Causing AIDS |
Ans:
| Column I | Column II |
| (a) Bacteria (b) Rhizobium (c) Lactobacillus (d) Yeast (e) A protozoan (f) A virus |
(i) Causing cholera (ii) Fixing nitrogen (iii) Setting of curd (iv) Baking of bread (v) Causing malaria (vi) Causing AIDS |
2. Name microorganisms which can fix atmospheric nitrogen in the soil.
Ans: Rhizobium and Clostridium fix atmospheric nitrogen.
3. What are the major groups of microorganisms
Ans: The major groups of microorganisms are Bacteria Fungi Protozoa Algae and Virus.
4. Name two diseases caused by (i) viruses (ii) protozoans
Ans: (i) Influenza and Cough. (ii) Dysentery and Malaria.
5. Which microorganisms are unicellular
Ans: Bacteria and protozoa are unicellular microorganisms .
6. Name two multicellular microorganisms.
Ans: Algae and fungi are multicellular microorganisms .
7. Name the bacterium used for production of acetic acid from alcohol.
Ans : The bacterium used for production of acetic acid from alcohol are Acetic Acid Bacteria. ( AAB)
8. Define fermentation.
Ans: The process of conversion of sugar into alcohol is called fermentation.
9. Why antibiotics are not effective against cold and flu.
Ans: Cold and flu are caused by viruses, so the antibiotics are not effective against them. Antibiotics are effective against bacteria not virus.
10. What are antibodies.
Ans::When a disease carrying microbe enters our body, the body produces antibodies to fight the invader.
11. Name two diseases which can be prevented by vaccination.
Ans: Cholera and Tuberculosis can be prevented by vaccination.
12. Name the diseases for which oral drops are given as vaccination.
Ans: The diseases for which oral drops are given as vaccination is Polio.
13. What are biological nitrogen fixers.
Ans: Some bacteria and blue-green algae are able to fix nitrogen from the atmosphere to enrich soil with nitrogen and increase fertility, are known as biological nitrogen fixers.
14. What are pathogens.
Ans: Diseases-causing microorganisms are called pathogens.
15. What are communicable diseases.
Ans: Microbial diseases which can spread from an infected person to a healthy person through air, water, food or physical contact are known as communicable diseases.
16. Name two communicable diseases.
Ans: Chicken pox and tuberculosis.
17. Name two carriers of disease-causing microbes.
Ans: Two carriers of disease-causing microbes are the Housefly and female Anopheles mosquito.
18. Name the causative microorganism of tuberculosis and its mode of transmission.
Ans: Causative microorganisms – Bacteria.
Mode of transmission – Air.
19. How are Cholera and Typhoid transmitted.
Ans: Cholera is transmitted through water or food. Typhoid is transmitted through water.
20. Which microorganism causes foot and mouth disease of cattle.
Ans: The microorganism that causes foot and mouth disease of cattle is the Virus.