Practice Questions →

Chapter 10: Microbes in Human Welfare

NCERT Solutions for CBSE Class 10 Biology — 18 solved questions with detailed explanations.

18

Questions

0

Topics

Solved Questions

Q1. Penicillin was discovered by:

Edward Jenner
Alexander Fleming
Louis Pasteur
Robert Koch

Difficulty: Easy · Topic: Antibiotics

Solution

Alexander Fleming discovered penicillin in 1928 from Penicillium notatum (mold contaminating bacterial culture).

Q2. The microorganism used in the production of ethanol is:

Lactobacillus
Saccharomyces cerevisiae
E. coli
Acetobacter

Difficulty: Easy · Topic: Fermentation

Solution

Saccharomyces cerevisiae (baker's/brewer's yeast) ferments sugars to ethanol and CO₂.

Q3. Lactobacillus is used in:

antibiotic production
bread making
curd/yogurt making
alcohol production

Difficulty: Easy · Topic: Microbes in Human Welfare

Solution

curd/yogurt making.

Q4. Acetobacter aceti produces:

citric acid
acetic acid (vinegar)
lactic acid
ethanol

Difficulty: Easy · Topic: Microbes in Human Welfare

Solution

acetic acid (vinegar).

Q5. Aspergillus niger produces:

penicillin
ethanol
acetic acid
citric acid

Difficulty: Easy · Topic: Microbes in Human Welfare

Solution

citric acid.

Q6. Biogas mainly contains:

methane (CH₄)
O₂
CO₂
N₂

Difficulty: Easy · Topic: Microbes in Human Welfare

Solution

methane (CH₄).

Q7. Methanobacterium produces:

oxygen
hydrogen
methane in biogas plants
nitrogen

Difficulty: Easy · Topic: Microbes in Human Welfare

Solution

methane in biogas plants.

Q8. Baculoviruses are used as:

biological pest control agents
food
fertilizer
medicine

Difficulty: Easy · Topic: Microbes in Human Welfare

Solution

biological pest control agents.

Q9. Yogurt/curd is made using:

Saccharomyces
Lactobacillus
E. coli
Penicillium

Difficulty: Easy · Topic: Microbes in Human Welfare

Solution

Lactobacillus.

Q10. Bread making uses:

Saccharomyces cerevisiae
Aspergillus
E. coli
Lactobacillus

Difficulty: Easy · Topic: Microbes in Human Welfare

Solution

Saccharomyces cerevisiae.

Q11. Cheese ripening uses:

Penicillium roqueforti/camemberti
Lactobacillus
E. coli
Saccharomyces

Difficulty: Easy · Topic: Microbes in Human Welfare

Solution

Penicillium roqueforti/camemberti.

Q12. Citric acid is produced by:

Saccharomyces
Aspergillus niger
Lactobacillus
Acetobacter

Difficulty: Easy · Topic: Microbes in Human Welfare

Solution

Aspergillus niger.

Q13. Vitamin B12 is produced commercially by:

E. coli
yeast
Pseudomonas denitrificans
Lactobacillus

Difficulty: Easy · Topic: Microbes in Human Welfare

Solution

Pseudomonas denitrificans.

Q14. Cyclosporin A (immunosuppressant) is from:

E. coli
Trichoderma polysporum
Penicillium
Streptomyces

Difficulty: Easy · Topic: Microbes in Human Welfare

Solution

Trichoderma polysporum.

Q15. Statin (cholesterol-lowering) is from:

Penicillium
Streptomyces
Monascus purpureus
E. coli

Difficulty: Easy · Topic: Microbes in Human Welfare

Solution

Monascus purpureus.

Q16. Sewage treatment primary step involves:

chemical treatment
nothing
physical removal of solids
biological treatment

Difficulty: Easy · Topic: Microbes in Human Welfare

Solution

physical removal of solids.

Q17. Activated sludge in sewage contains:

nothing
only chemicals
only sand
aerobic bacteria and fungi

Difficulty: Easy · Topic: Microbes in Human Welfare

Solution

aerobic bacteria and fungi.

Q18. BOD of clean water is:

zero always
high
very high
low (< 5 mg/L)

Difficulty: Easy · Topic: Microbes in Human Welfare

Solution

low (< 5 mg/L).

Other Chapters in Biology

Ch 1: Reproduction in Organisms Ch 2: Sexual Reproduction in Plants Ch 3: Human Reproduction Ch 4: Reproductive Health Ch 5: Principles of Inheritance Ch 6: Molecular Basis of Inheritance Ch 7: Evolution Ch 8: Human Health & Disease Ch 9: Strategies for Enhancement Ch 11: Biotechnology Principles Ch 12: Biotechnology Applications Ch 13: Organisms & Populations Ch 14: Ecosystem Ch 15: Biodiversity & Conservation Ch 16: Environmental Issues

Want to practice these questions interactively?

Get instant feedback, track progress, and improve with adaptive practice.

Start Practicing Free →