Microbes in Human Welfare Class 12 MCQs Questions with Answers

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

2. Citric acid is produced by:

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

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

5. Azoila has symbiotic relationship with:

6. Lactic acid is formed by the process of

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

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

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

10. Process of biogas production is

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

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

13. Methanogens do not produce

14. Term antibiotic was first used by :

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

16. Bacillus thuringiensis is used to control

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

18. Usnic acid is an antibiotic obtained from :

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

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