Page 2 - Assignment-Microbes in Human Welfare

9. Before antibiotics, the first commercial antibacterial available was _____
a. Penicillin
b. Prontosil
c. Azithromycin
d. None of the above
10. Example of a natural insect repellant
a. Citronella oil
b. Coconut oil
c. Linseed oil
d. None of the above

B. Very Short Answer Questions (1 mark each)
1. How does a small amount of curd added to fresh milk convert it into curd? Mention a
nutritional quality that gets added to the curd.
2. Why is secondary treatment of water in sewage treatment plant called biological
treatment?
3. An antibiotic called ‘Wonder Drug’ was used to treat the wounded soldiers of
America during World War-II. Name the drug and the scientist who discovered it.
4. You have observed that fruit juice in bottles bought from the market is clearer as
compared to those made at home. Give reason.
5. Alexander Fleming discovered ‘Penicillin, but its full potential as an effective
antibiotic was established by other scientists. Name the two scientists.
6. Name the plant whose sap is used in making ‘Toddy’. Mention the process involved in
it.

C. Short Answer Questions-II (2 marks each)
7. Name two alcoholic drinks produced in each of the following ways.
(i) by distillation and (ii) without distillation.
8. Lactic Acid Bacteria (LAB) is commonly used in the conversion of milk into curd.
Mention any two other functions of LAB that are useful to humans.
9. How do mycorrhizae function as biofertilisers? Explain with example.
10.Cyanobacteria (Nostoc, Anabaena) are used as biofertilisers in certain crop fields.
Name such one crop. Also, mention the names of two other microorganisms which
perform the same function.
11. Which Ministry of Govt. of India had initiated Ganga Action Plan and Yamuna Action
Plan? What are the objectives of these plans?

D. Short Answer Questions-I (3 marks each)
12. Fill in the blanks spaces a, b, c, d, e, and f, given in the following table :