Chapter-16 Microorganisms — Online MCQ Test
SCIENCE · Samacheer Kalvi 8th · Tamil Nadu State Board
Practice Chapter-16 Microorganisms with a free chapter-wise online MCQ test.
This chapter covers: bacteria fungi virus Covers useful and harmful microorganisms in daily life.
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter-16 Microorganisms — Important Questions & Answers
Which of the following microorganisms is used in making curd?
- A. Bacteria
- B. Virus
- C. Protozoa
- D. Algae
Answer: A. Bacteria
Lactobacillus, a bacterium, converts milk into curd by producing lactic acid.
Lactobacillus, a bacterium, converts milk into curd by producing lactic acid.
Which microorganism is commonly used in baking bread?
- A. Rhizobium
- B. Yeast
- C. Amoeba
- D. Plasmodium
Answer: B. Yeast
Yeast is a fungus used in baking because it releases carbon dioxide and makes the dough rise.
Yeast is a fungus used in baking because it releases carbon dioxide and makes the dough rise.
Which of the following is NOT a microorganism?
- A. Bacteria
- B. Fungi
- C. Virus
- D. Mango tree
Answer: D. Mango tree
A mango tree is a plant and not a microorganism. Microorganisms are too small to be seen without a microscope.
A mango tree is a plant and not a microorganism. Microorganisms are too small to be seen without a microscope.
Which statement best explains why fungi are useful in medicine?
- A. They produce vaccines naturally
- B. Some fungi produce antibiotics like penicillin
- C. They convert milk into curd
- D. They fix nitrogen in soil
Answer: B. Some fungi produce antibiotics like penicillin
Certain fungi, such as Penicillium, are used to produce antibiotics that kill harmful bacteria.
Certain fungi, such as Penicillium, are used to produce antibiotics that kill harmful bacteria.
Which of the following is the most appropriate reason for adding yeast to dough with sugar and warm water?
- A. To make the dough acidic and hard
- B. To stop microbial growth completely
- C. To produce carbon dioxide that makes the dough rise
- D. To convert flour into curd
Answer: C. To produce carbon dioxide that makes the dough rise
Yeast ferments sugar and releases carbon dioxide, which causes the dough to expand and rise.
Yeast ferments sugar and releases carbon dioxide, which causes the dough to expand and rise.