MCQ Questions for Class 8 Science: Ch 2 Microorganisms: Friend and Foe
1. Identify bacteriophage.
(a) Algae
(b) Virus
(c) Protozoa
(d) Fungi
► (b) Virus
2. Microbiology is the study of :
(a) Useful products prepared from microbes
(b) Parts of living organisms
(c) Microbes
(d) Diseases caused by microorganisms
► (c) Microbes
3. _______ are the agents that act as carriers of a pathogen and spread diseases.
(a) Microbes
(b) Parasites
(c) Vectors
(d) DNA
► (c) Vectors
4. Rhizobium bacteria
(a) Help in digestion
(b) Cause diseases
(c) Help in nitrogen fixation
(d) All of these
► (c) Help in nitrogen fixation
5. Malaria is caused by
(a) Protozoa
(b) Virus
(c) Algae
(d) Bacteria
► (a) Protozoa
6. Scientists who study microorganisms are called
(a) microbiologists
(b) microscopists
(c) microorganists
(d) microtypist
► (a) microbiologists
7. The moist bread becomes mouldy after a few days when it is left in a container with a cover. Which of the following conditions favour the growth of the fungus?
(a) Absence of water
(b) Absence of light
(c) Presence of sunlight
(d) Presence of carbon dioxide
► (b) Absence of light
8. What process takes place when yeast is added to grape juice and left for a week?
(a) Decomposition
(b) Fermentation
(c) Distillation
(d) Oxidation
► (b) Fermentation
9. Which is a fungal disease in human?
(a) amoebiasis
(b) tuberculosis
(c) anthrax
(d) Athlete’s foot
► (d) Athlete’s foot
10. Which of the following disease causing pathogens is / are carried by mosquitoes?
(a) Dengue fever
(b) Malaria
(c) Cholera
(d) Both (A) and (B)
► (d) Both (A) and (B)
11. Which of the following terms is given to the microorganisms that cause diseases?
(a) Antigens
(b) Antibodies
(c) Pathogens
(d) Vectors
► (c) Pathogens
12. Amoeba belongs to
(a) Algae
(b) Fungi
(c) Protozoa
(d) Virus
► (c) Protozoa
13. Yeast is not used in the preparation of :
(a) bread
(b) alcohol
(c) dhokla
(d) antibiotic
► (d) antibiotic
14. Microorganisms are :
(a) saprophytes
(b) autotrophs
(c) autotrophs & heterotrophs
(d) hetrotrophs
► (c) autotrophs & heterotrophs
15. Which of the following can affectively prevent the ringworm disease?
(a) Vaccination
(b) Vector control
(c) Improving personal hygiene
(d) Using antibiotics
► (c) Improving personal hygiene
16. What are pond scum?
(a) algae
(b) protozoa
(c) fungi
(d) bacteria
► (a) algae
17. A plant disease called citrus canker is caused by a _________ .
(a) Virus
(b) Protozoa
(c) Bacteria
(d) Fungi
► (c) Bacteria
18. Bacteriophage is a :
(a) fungi
(b) protozoa
(c) virus
(d) bacteria
► (c) virus
19. Which of the following statements describes bacteriophage correctly?
(a) It is a bacterium which causes diseases in plants.
(b) It is a type of virus which attacks bacteria.
(c) It is a bacterium which kills viruses.
(d) It can multiply inside both living and non-living cells.
► (b) It is a type of virus which attacks bacteria.
20. Which of the following is the smallest microorganism?
(a) Algae
(b) Bacterium
(c) Protozoan
(d) Virus
► (d) Virus
21. Which of the following enzymes is secreted by bacteria that can digest cellulose?
(a) Amylase
(b) Cellulase
(c) Lipase
(d) Protease
► (b) Cellulase
22. Which of the following microorganism lives alone:
(a) Amoeba
(b) All Bacteria
(c) Fungi
(d) All Cyanobacteria
► (a) Amoeba
23. Which two words are synonyms?
(a) Microorganism and pathogen
(b) Microorganism and microbe
(c) Microbe and aerobe
(d) Microbe and anaerobe
► (b) Microorganism and microbe
24. Curd formations needs :
(a) citric acid bacterium
(b) acetic acid bacterium
(c) lactic acid bacterium
(d) all the above
► (c) lactic acid bacterium
25. TMV causes disease in :
(a) tobacco plant
(b) human infants
(c) timber plants
(d) none of the above
► (a) tobacco plant
26. Scientist who discovered the fermentation
(a) Alexander Fleming
(b) Louis Pasteur
(c) John Mendal
(d) Charles Darwin
► (b) Louis Pasteur