Microbiology MCQ with answers pdf | Microbiology MCQs online test | Microbes in Healthcare & Medicine

1. Primary sludge is used for

(a) preparation of compost

(b) preparation of manure

(c) biogas production

(d) All of the above

Ans. d

2. Some blue-green algae are used as bio fertilisers because they

(a) are photosynthetic 

(b) have mucilage

(c) grow everywhere

(d) fix nitrogen

Ans. d

3. The bacterium which is used in the prepartion of vitamin riboflavin is

(a) Leuconostoc

(b) Clostridium butylicum

(c) Lactobacillus

(d) None of these 

Ans. b

4. Passage of effluents into oxidation tank is for

(a) primary treatment

(b) secondary treatment

(c) tertiary treatment

(d) Both (a) and (b)

Ans. b

5. Cyclosporin-A is used for

(a) dissolving blood clots

(b) lowering cholesterol level

(c) immunosuppression

(d) enhancing tenderness of meat

Ans.  c

6. Lactic acid is used in

(a) preservation 

(b) tanning

(c) plastic making

(d) All of these

Ans. d

7. Biological control component is controlled to advanced agricultural production, which of the following is used as a third generation pesticide?

(a) Insect hormone analogues

(b) Insect repellents

(c) Pheromones

(d) Pathogens

Ans. a

8. Acommon biocontrol agent for the control of plant disease is

(a) Baculovirus

(b) Bacillus thuringiensis

(c) Glomus

(d) Trichoderma  

Ans. d

9. Which of the following is not used as biopesticide?

(a) Bacillus thuringiensis

(b) Tríchoderma harzianum

(c) Nuclear polyhedrosis virus

(d) Xanthomonas compestris

Ans. d

10. Sporeine is a bioinsecticide, based on Bacillus  thuringiensis (Bt). It was developed in Germany and kills insects by inhabiting ion transport in

(a) foregut 

(b) midgut

(c) hindgut

(d) digestive system

Ans. b

Microbiology NEET PG MCQ books pdf

11. A non-photosynthetic aerobic nitrogen fixing soil bacteria

(a) Rhizobium

(b) Clostridium

(c) Azotobacter

(d) Klebsiella

Ans. d

12. A fungus used for the biocontrol of plant pathogens is

(a) Trichoderma viridae

(b) Mucor mucedo

(c) Penicillium notatum

(d) Phytophthora parasitica

Ans. a

13. Lepidopterous are used as

(a) biofertilisers 

(b) healthcare agents

(c) biological control

(d) None of these

Ans. c

14. Which of the following is used as biological controb

(a) Albugo 

(b) Puccinia

(c) Phytophthora

(d) None of these

Ans. c

15. Azotobacter is used as

(a) biofertilisers

(b) biological control

(c) Both (a) and (b)

(d) None of these

Ans. a

16. Primary treatment of sewage is

(a) physical process 

(b) biological process

(c) chemical process

(d) biochemical process

Ans. a

Bacteria multiple choice questions and answers pdf | Medical microbiology mcqs pdf free download

17. Farmyard manure and compost are prepared by bacterial action from

(a) refuse 

(b) garbage

(c) animal excreta

(d) All of these

Ans. d

18. Which one is a biofertiliser?

(a) NPK mixture

(b) Rhizobia in legume roots

(c) Rhizobia in farmyard manure

(d) Green manure

Ans. b

19. Passage of effluents into oxidation tank is used for  

(a) primary treatment

(b) secondary treatment

(c) Both (a) and (b)

(d) tertiary treatment

Ans. b

20. Which of the following can be controlled by using biopesticides?

(a) Insects 

(b) Diseases

(c) Weeds

(d) All of these

Ans. d

21. Most common nitrogen-fixing cyanobacterium of padey fields is

(a) Cylindrospermum 

(b) Aulosira

(c) Oscillatoria

(d) Nostoc 

Ans. b

22. Cheese and yogurt are the products of

(a) S. greisas 

(b) Lactobbacillus

(c) Streptococcus

(d) R. orzyae

Ans. c

General Microbiology Multiple Choice Questions | Microbiology MCQ Book PDF Download

23. ‘Palmivoralt’ is a

(a) herbicide 

(b) fungicide

(c) nematocide

(d) rodenticide

Ans. a

24. Some blue-green algae are used as biofertiliser as they

(a) fix nitrogen

(b) are mucilaginous

(c) can grow everywhere

(d) are deficient in nutrient

Ans. a

25. Soil microorganisms are mainly comprised of

(a) fungi

(b) fungi and bacteria

(c) fungi, bacteria and Actinomycetes

(d) None of the above  

Ans. c

26. Which one of the following groups of bacteria supplies nitrogen to our crop plants irrespective of crop rotation or manuring?

(a) Nitrosomonas 

(b) Nitrobacter

(c) Rhizobium

(d) Azotobacter

Ans. b

27. An organism used as a biofertiliser for raising soybean crop production is

(a) Azospirillum

(b) Rhizobium

(c) Nostoc

(d) Azotobacter

Ans. d

28. Biofertilisers give better yield when added along with

(a) phosphate 

(b) calcium

(c) nitrogen

(d) urea

Ans. a

29. BGA is chiefly used as biofertiliser in the crops of 

(a) wheat

(b) gram

(c) paddy

(d) mustard

Ans. c

30. Symbiotic nitrogen fixing bacteria belongs to

(a) Xanthomonas 

(b) Acetobacter

(c) Pseudomonas

(d) Rhizobium

Ans. d

Microbiology Multiple Choice Questions and Answers PDF

31. Which one of the following is used as biological insecticide?

(a) Silkmoth

(b) Caterpillar 

(c) Mazra bok

(b) Tiger bettle

Ans. c

32. During anerobic digestion of organic waste, such as in producing biogas, which one of the following is left undergraded?

(a) Hemicellulose 

(b) Lignin

(c) Lipids

(d) Cellulose


33. Bacillus thuringiensis (Bt) strains have been used for designing novel

(a) biofertiliser

(b) bio-mineralisation processes

(c) bio-insecticidal plants

(d) bio-metallurgical techniques

Ans. c

34. Leghaemoglobin is a

(a) respiratory pigment in humans

(b) pigment present in leguminous plant

(c) Both (a) and (b)

(d) None of these

Ans. d

35. The common nitrogen-fixer in paddy fields in 

(a) Frankia

(b) Rhizobium

(c) Azospirillum

(d) Oscillatoria 

Ans. c

36. Which of the following is mainly produced by the activity of anaerobic bacteria on sewage?

(a) Marsh gas 

(b) Laughing gas

(c) Propane

(d) Mustard gas

Ans. a

37. Agriculture by using only biofertilisers is called 

(a) manuring

(b) composting

(c) inorganic farming

(d) organic farming 

Ans. d

38. Cyanobacteria serves as important biofertilisers in the fields of   

(a) rice

(b) maize

(c) wheat

(d) sugarcane

Ans. a

39. Physical removal of large and small from the sewage through filtration and sedimentation is called

(a) primary treatment

(b) secondary treatment

(c) tertiary treatment

(d) quaternary treatment

Ans. a

40. Secondary sewage treatment is mainly a 

(a) biological process

(b) physical process

(c) mechanical process

(d) chemical process

Ans. a

41. The ergot of rye is caused by chemical

(a) ergotinine

(b) heparin

(c) histamine

(d) arginine

Ans. a

42. Nitrogen-fixation is performed by

(a) green alga and fungi

(b) mycorrhiza

(c) mycoplasma

(d) blue-green algae and bacteria

Ans. d

43. Nitrifying bacteria are

(a) chemosynthetic 

(b) photoautotrophic

(c) parasitic

(d) saprotrophic

Ans. a

44. Nitrosomonas is a

(a) photoautotroph 

(b) chemoautotroph

(c) chemoheterotroph

(d) photoheterotroph

Ans. b

45. Symbiotic nitrogen-fixing bacteria belong to  

(a) Xanthomonas

(b) Acetobacter

(c) Pseudomonas

(d) Rhizobium

Ans. d

46. One of the following is a biofertiliser rich in free living nitrogen-fixing bacteria

(a) Rhizobium 

(b) Micrococcus

(c) Pyrethrin

(d) Azotobacter


47. Biogas is

(a) cheaper fuel

(b) ecofriendly fuel

(c) renewable source of energy 

(d) All of the above

Ans. d

48. Gobar gas is produced by

(a) nitrifying bacteria 

(b) methanogenic bacteria

(c) lactogenic bacteria

(d) oxidising bacteria

Ans. b

49. Thuricide is a proteinaceous toxin, which is obtained from

(a) biofertiliser 

(b) bacterial origin

(c) green manure

(d) farmyard manure

Ans. b

50. Farmers have reported 50% higher yields of rice by using the biofertiliser

(a) mycorrhiza

(b) Azolla pinnata

(c) cyanobacteria

(d) legume-Rhizobium symbiosis

Ans. b