Chapter 9: Microbes in Human Welfare — Online MCQ Test
ZOOLOGY · CLASS 12th · Tamil Nadu State Board
Practice Chapter 9: Microbes in Human Welfare with a free chapter-wise online MCQ test.
This chapter covers: Focusing on practical biological applications this chapter details microbial roles in household products industrial fermentation sewage treatment biogas production and pest control....
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter 9: Microbes in Human Welfare — Important Questions & Answers
Which microorganism is commonly used in the production of curd from milk?
- A. Lactobacillus
- B. Saccharomyces
- C. Rhizobium
- D. Plasmodium
Answer: A. Lactobacillus
Lactobacillus converts milk sugar into lactic acid, which helps in curd formation. It is a lactic acid bacterium used in household fermentation.
Lactobacillus converts milk sugar into lactic acid, which helps in curd formation. It is a lactic acid bacterium used in household fermentation.
Which of the following is used in bread and beer production?
- A. Bacteria
- B. Yeast
- C. Algae
- D. Protozoa
Answer: B. Yeast
Yeast, especially Saccharomyces cerevisiae, ferments sugars to produce carbon dioxide and alcohol. This makes it useful in bread and beer preparation.
Yeast, especially Saccharomyces cerevisiae, ferments sugars to produce carbon dioxide and alcohol. This makes it useful in bread and beer preparation.
In sewage treatment, the activated sludge is mainly rich in:
- A. Viruses
- B. Protozoans
- C. Flocs of bacteria
- D. Fungi only
Answer: C. Flocs of bacteria
Activated sludge contains flocs mainly made of bacteria along with fungal filaments. These microbes help decompose organic wastes in sewage.
Activated sludge contains flocs mainly made of bacteria along with fungal filaments. These microbes help decompose organic wastes in sewage.
Which of the following is NOT correctly matched?
- A. Curd formation - Lactobacillus
- B. Biogas production - Methanogens
- C. Cheese ripening - Penicillium
- D. Antibiotic production - Rhizobium
Answer: D. Antibiotic production - Rhizobium
Rhizobium is a nitrogen-fixing bacterium, not an antibiotic-producing organism. Antibiotics are generally produced by microbes like Streptomyces and Penicillium.
Rhizobium is a nitrogen-fixing bacterium, not an antibiotic-producing organism. Antibiotics are generally produced by microbes like Streptomyces and Penicillium.
Which option correctly identifies the organism and its product used in genetic engineering and pest control?
- A. Rhizobium - curd
- B. Bacillus thuringiensis - Bt toxin
- C. Aspergillus niger - penicillin
- D. Saccharomyces cerevisiae - nitrogen fixation
Answer: B. Bacillus thuringiensis - Bt toxin
Bacillus thuringiensis produces Bt toxin, which is used in biopesticides and transgenic crops. The other options are mismatched with their products or functions.
Bacillus thuringiensis produces Bt toxin, which is used in biopesticides and transgenic crops. The other options are mismatched with their products or functions.