Microbes in Human Welfare Class 12 MCQs Questions with Answers

1. Term antibiotic was first used by :

2. Which of the followings is mainly produced by the activity of anaerobic bacteria on sewage?

3. Lactic acid is formed by the process of

4. BOD of wastewater is estimated by measuring the amount of

5. The vitamin whose content increases following the conversion of milk into curd by lactic acid bacteria is

6. Bacillus thuringiensis is used to control

7. The nutritive medium for growing bacteria and many fungi in laboratory is called

8. Methanogens do not produce

9. The residue left after methane production from cattle dung is

10. Process of biogas production is

11. Which one of the following is not a nitrogenfixing organism?

12. Citric acid is produced by:

13. During the primary treatment of sewage, solid particles that settle down are called

14. Which of the following is widely used as a successful biofertiliser in Indian rice field ?

15. The chemical substances produced by some microbes which can kill or retard the growth of other microbes are called

16. Which one of the following is not used in organic farming?

17. Usnic acid is an antibiotic obtained from :

18. For retting of jute, the fermenting microbe is:

19. Azoila has symbiotic relationship with:

20. Which one of the following can be used as biofertiliser in cotton field ?