Microbes in Human Welfare Class 12 MCQs Questions with Answers

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

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

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

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

5. Citric acid is produced by:

6. Usnic acid is an antibiotic obtained from :

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

8. Process of biogas production is

9. Bacillus thuringiensis is used to control

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

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

12. Lactic acid is formed by the process of

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

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

15. Azoila has symbiotic relationship with:

16. Methanogens do not produce

17. Term antibiotic was first used by :

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

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

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