12th Biology Microbes in Human Welfare Objective Questions

1. Microbes are found

(A) in soil

(B) in air

(C) in water

(D) everywhere

[Ans. (D)]

2. The microscopic proteinous infectious agents are called

(A) protozoa

(B) fungi

(C) prions

(D) bacteria

(Ans. (C)]

3. The nutritive media for growing bacteria and other microorganisms in the laboratory is called

(A) colonies

(B) culture media

(C) baking media

(D) fermentation

(Ans. (B)]

4. Who initiated Ganga and Yumna Action plan?


(B) Ministry of Environment and forest


(D) None


5. Which role is played by lactic acid bacteria (LAB) in our stomach?

(A) Beneficial

(B) Harmful

(C) Neutral

(D) All of these

[Ans. (A)]

6. The dough used for making bread is fermented by

(A) bacteria

(B) Yeast

(C) fungi

(D) algae

[Ans. (B)]

7. Which of the following is used in preparing cheese?

(A) algae

(B) viruses

(C) microbes

(D) prions


8. The large vessels for growing microbes on an industrial scale are called

(A) Petri dish

(B) digestors

(C) biogas vessel

(D) fermenters

[Ans. (D)]

9. Which of the following organisms is used in the production of beverages?

(A) Penicillium notatum

(B) Saccharomyces cerevisiae

(C) Aspergillus niger

(D) Clostridium butylicum

[Ans. (B)]

10. The gas responsible for puffing-up appearance of dough comes from

(A) aerobic respiration

(B) fermentation

(C) photosynthesis

(D) photorespiration

[(Ans. (B)]

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

(A) toddy

(B) lactic acid

(C) antibiotics

(D) ethanol


12. Which of the following antibiotics was discovered first?

(A) Streptomycin

(B) Neomycin

(C) Erythromycin

(D) Penicillin

[(Ans. (D)]

13. Acetic acid is produced by a

(A) fungus

(B) bacterium

(C) Yeast

(D) virus

[(Ans. (B)]

14. Citric acid is produced by

(A) Acetobacter aceti

(a) bacterium)

(B) Yeast (a fungus)

(C) Aspergillus niger (a fungus)

(D) Streptococcus (a bacterium)


Leave a Comment

Your email address will not be published. Required fields are marked *

You cannot copy content of this page

error: Content is protected !!