36 MCQ Questions for Class 8 Science: Chapter 2 Microorganisms: Friend and Foe
Question 1. What are microorganisms also known as?
a) Mini-organisms
b) Microbes
c) Small plants
d) Tiny animals
Answer:
b) Microbes
Question 2. Which of the following is not a type of microorganism?
a) Bacteria
b) Fungi
c) Algae
d) Amoeba
Answer:
d) Amoeba
Question 3. What is the role of Lactobacillus in the formation of curd?
a) It spoils the milk.
b) It ferments the milk sugars.
c) It adds flavor to the milk.
d) It cools down the milk.
Answer:
b) It ferments the milk sugars.
Question 4. What process is used in the making of bread and cake?
a) Pasteurization
b) Fermentation
c) Distillation
d) Filtration
Answer:
b) Fermentation
Question 5. Who discovered fermentation in 1857?
a) Edward Jenner
b) Alexander Fleming
c) Louis Pasteur
d) Robert Koch
Answer:
c) Louis Pasteur
Question 6. Which microorganism is used for the commercial production of alcohol?
a) Bacteria
b) Virus
c) Fungi
d) Yeast
Answer:
d) Yeast
Question 7. What is the common carrier of communicable diseases?
a) Ant
b) Spider
c) Housefly
d) Butterfly
Answer:
c) Housefly
Question 8. What does a vaccine do?
a) It kills bacteria.
b) It strengthens the immune system.
c) It provides immediate cure.
d) It stops physical symptoms.
Answer:
b) It strengthens the immune system.
Question 9. Which microorganism is involved in the fixation of nitrogen in leguminous plants?
a) Rhizobium
b) Lactobacillus
c) Yeast
d) Algae
Answer:
a) Rhizobium
Question 10. What are antibiotics used for?
a) Killing or stopping the growth of disease-causing microorganisms
b) Enhancing the growth of microorganisms
c) Fermenting bread and cake
d) Fixing atmospheric nitrogen
Answer:
a) Killing or stopping the growth of disease-causing microorganisms
Question 11. Which of these diseases is not caused by bacteria?
a) Tuberculosis
b) Anthrax
c) Cholera
d) Common cold
Answer:
d) Common cold
Question 12. What is the role of yeast in the production of alcohol?
a) Fermentation of sugars
b) Purification of alcohol
c) Filtering impurities
d) Adding flavor
Answer:
a) Fermentation of sugars
Question 13. Which of these is not a method of food preservation?
a) Salting
b) Fermentation
c) Pasteurization
d) Freezing
Answer:
b) Fermentation
Question 14. What is the main cause of food poisoning?
a) Consumption of food exposed to heat
b) Eating uncooked food
c) Consumption of food contaminated by microorganisms
d) Use of preservatives in food
Answer:
c) Consumption of food contaminated by microorganisms
Question 15. What is the primary function of antibiotics?
a) To promote the growth of microorganisms
b) To kill or stop the growth of harmful microorganisms
c) To enhance the taste of food
d) To cure diseases caused by viruses
Answer:
b) To kill or stop the growth of harmful microorganisms
Question 16. Which microorganism is used in the preparation of curd?
a) Yeast
b) Lactobacillus
c) Rhizobium
d) Penicillin
Answer:
b) Lactobacillus
Question 17. How do vaccines work?
a) By killing pathogens directly
b) By producing antibodies
c) By increasing body temperature
d) By providing immediate cure
Answer:
b) By producing antibodies
Question 18. Which of these is a viral disease?
a) Typhoid
b) Tuberculosis
c) Common cold
d) Anthrax
Answer:
c) Common cold
Question 19. What is the role of microorganisms in the nitrogen cycle?
a) They fix atmospheric nitrogen
b) They convert nitrogen into oxygen
c) They eliminate nitrogen from the atmosphere
d) They have no role in the nitrogen cycle
Answer:
a) They fix atmospheric nitrogen
Question 20. Which of these is not used as a food preservative?
a) Salt
b) Sugar
c) Vinegar
d) Yeast
Answer:
d) Yeast
Question 21. Yeast is used in the production of:
a) Sugar
b) Alcohol
c) Hydrochloric acid
d) Oxygen
Answer:
b) Alcohol
Question 22. The following is an antibiotic:
a) Sodium bicarbonate
b) Streptomycin
c) Alcohol
d) Yeast
Answer:
b) Streptomycin
Question 23. Carrier of malaria-causing protozoan is:
a) Female Anopheles mosquito
b) Cockroach
c) Housefly
d) Butterfly
Answer:
a) Female Anopheles mosquito
Question 24. The most common carrier of communicable diseases is:
a) Ant
b) Housefly
c) Dragonfly
d) Spider
Answer:
b) Housefly
Question 25. The bread or idli dough rises because of:
a) Heat
b) Grinding
c) Growth of yeast cells
d) Kneading
Answer:
c) Growth of yeast cells
Question 26. The process of conversion of sugar into alcohol is called:
a) Nitrogen fixation
b) Moulding
c) Fermentation
d) Infection
Answer:
c) Fermentation
Fill in the blank Questions
Question 27. Microorganisms can be seen with the help of a ____________.
Answer:
Microscope
Question 28. Blue green algae fix __________ directly from air and enhance fertility of soil.
Answer:
Nitrogen
Question 29. Alcohol is produced with the help of __________.
Answer:
Yeast
Question 30. Cholera is caused by __________.
Answer:
Bacteria
Question 31. __________ is used in bakeries to make bread and pastries rise.
Answer:
Yeast
Question 32. The process of __________ helps in making curd from milk.
Answer:
Fermentation
Question 33. Penicillin is an antibiotic that is obtained from __________.
Answer:
Fungi
Question 34. __________ is a disease caused by protozoans.
Answer:
Malaria
Question 35. The Rhizobium bacteria live in symbiotic association with __________ plants.
Answer:
Leguminous
Question 36. __________ are microorganisms that are used to clean up the environment.
Answer:
Bacteria
Match the Following Question
Question
| Column A | Column B |
|---|---|
| (i) Lactobacillus | (a) Causes malaria |
| (ii) Yeast | (b) Used in making curd |
| (iii) Rhizobium | (c) Used in baking and alcohol production |
| (iv) Penicillium | (d) Fixes nitrogen in soil |
| (v) Plasmodium | (e) Antibiotic production |
| (vi) Mycorrhizae | (f) Symbiotic association with plant roots |
Answer
| Column A | Column B |
|---|---|
| (i) Lactobacillus | (b) Used in making curd |
| (ii) Yeast | (c) Used in baking and alcohol production |
| (iii) Rhizobium | (d) Fixes nitrogen in soil |
| (iv) Penicillium | (e) Antibiotic production |
| (v) Plasmodium | (a) Causes malaria |
| (vi) Mycorrhizae | (f) Symbiotic association with plant roots |
