Microbes in Human Welfare Class 12 MCQs Questions with Answers

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

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

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

4. Usnic acid is an antibiotic obtained from :

5. Term antibiotic was first used by :

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

7. Methanogens do not produce

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

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

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

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

12. Lactic acid is formed by the process of

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

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

15. Citric acid is produced by:

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

17. Azoila has symbiotic relationship with:

18. Process of biogas production is

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

20. Bacillus thuringiensis is used to control