Class 12 · Biology · CBSE Board · 2016–2025

Microbes in Human Welfare — Class 12 Biology PYQs

67 questions from this chapter, asked in 9 Class 12 exams between 2016–2025 — every question paper set included, duplicates removed.

67questions

9Class 12 exams

2016–2025years covered

1 / 2 / 3 / 5mark values asked

Questions asked per year

202518 Qs 20245 Qs 20238 Qs 20228 Qs 20207 Qs 20196 Qs 201812 Qs 20176 Qs 20163 Qs

Practice questions first 10 of 67 — free

Q1MCQ20251 mark

Answer Logic

From which one of the following bacteria is Bt-toxin gene isolated ?
[Max Marks: 1 | Set: 57/2/3]

(A)Bacillus thuringiensis

(B)Bacillus subtilis

(C)Thermus aquaticus

(D)Agrobacterium tumefaciens

Q2MCQ20251 mark

Answer Logic

Match the columns and choose the correct option :
Column I Column II
(i) Methanogens
[Max Marks: 1 | Sets: 57/2/1]

(A)(i) - B, (ii) - D, (iii) - C, (iv) - A

(B)(i) - B, (ii) - C, (iii) - D, (iv) - A

(C)(i) - C, (ii) - B, (iii) - A, (iv) - D

(D)(i) - D, (ii) - A, (iii) - B, (iv) - C

Q3MCQ20251 mark

Answer Logic

Identify the correct match for Monascus purpureus :
[Max Marks: 1 | Sets: 57/1/3]

(A)Statins

(B)Citric acid

(C)Ethanol

(D)Cyclosporin A

Q4MCQ20251 mark

Answer Logic

Statins produced by yeast Monascus purpureus are used as :
[Max Marks: 1 | Sets: 57/2/2]

(A)Blood cholesterol lowering agents

(B)Clot buster

(C)Immunosuppressive agents

(D)Antibiotic

Q5MCQ20251 mark

Answer Logic

What is the approximate diameter of flocs that are formed in the secondary treatment of sewage ?
[Max Marks: 1 | Sets: 57/2/3]

(A)10-15 µm

(B)100-150 µm

(C)1-1.5 mm

(D)10-15 mm

Q6MCQ20251 mark

Answer Logic

Which one of the following is the most commonly used bioreactor ?
[Max Marks: 1 | Sets: 57/1/2]

(A)Simple stirred tank bioreactor

(B)Sparged stirred tank bioreactor

(C)Air lift bioreactor

(D)Fluidized bed bioreactor

Q7MCQ20251 mark

Answer Logic

Cyclosporin A, which is used as an immuno-suppressive drug during organ transplantation, is obtained from :
[Max Marks: 1 | Sets: 57/1/1]

(A)Bacteria

(B)Fungi

(C)Virus

(D)Protozoan

Q8MCQ20251 mark

Answer Logic

How much daily reduction in the level of blood cholesterol can be caused by the use of Statins ?
[Max Marks: 1 | Sets: 57/1/3]

(A)0.02%

(B)0.2%

(C)2%

(D)20%

Q9MCQ20251 mark

Answer Logic

How many of the following antibiotics were discovered from species of Streptomyces ?
Streptomycin, Chloramphenicol, Penicillin, Tetracycline, Neomycin, Erythromycin
[Max Marks: 1 | Sets: 57/2/2]

(A)Six

(B)Five

(C)Four

(D)Three

Q10MCQ20251 mark

Answer Logic

Which enzyme is used to remove the mucilaginous layer (pectinous material) from hemp fibres ?
[Max Marks: 1 | Sets: 57/1/2]

(A)Lipase

(B)Pectinase

(C)Protease

(D)Amylase

Why practise Microbes in Human Welfare PYQs?

Microbes in Human Welfare has appeared in 9 Class 12 Biology exams we track between 2016–2025, with questions worth 1, 2, 3, 5 marks. CBSE Board examiners consistently reuse concepts and question patterns from this topic — practising its previous year questions is the most reliable way to know exactly what to expect in your exam.

Microbes in Human Welfare — Class 12 Biology PYQs

Questions asked per year

Practice questions first 10 of 67 — free

Why practise Microbes in Human Welfare PYQs?

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