MCQ for Class 8 Microorganisms Science Chapter-wise

Q 1 – Alcohol is produced with the help of
(a) sodium chloride
(b) yeast
(c) nitrogen
(d) carbon dioxide

Ans 1 – (b) yeast

Q 2 –The host for malaria causing protozoan is:
(a) anapheles mosquito
(b) the cow
(c) the earthworm
(d) the tapeworm

Ans 2 – (a) anapheles mosquito
Anopheles mosquito is the host for malaria causing protozoan

Q 3 – The status of algae in the aquatic food chain is
(a) consumers
(b) producers
(c) host
(d) small in size

Ans 3 – (b) producers

Q 4 –The bread or dosa dough rises because of the action of:
(a) heat
(b) grinding
(c) growth of yeast cells
(d) none of these

Ans 4 – (c) growth of yeast cells
Due to growth of yeast cells, the breads or dosa dough rises

Q 5 – The rod-shaped bacteria are called
(a) Bacillus
(b) Coccus
(c) Vibrio
(d) Spirillum

Ans 5 –(a) Bacillus

Q 6 –Malaria is spread by:
(a) plasmodium
(b) female anapheles mosquito
(c) male anapheles mosquito
(d) none of these

Ans 6 –(b) female anapheles mosquito
Malaria is spread by female anapheles mosquito.

Q 7– The microorganism which contains chlorophyll
(a) Virus
(b) Fungus
(c) Algae
(d) All

Ans 7 –(c) Algae

Q 8 –The bacteria was first observed by:
(a) Louis Pasteur
(b) Antony Von Leuwen Hook
(c) Robert Hooke
(d) Robert Koch

Ans 8 –(b) Antony Von Leuwen Hook
The bacteria was first observed by Antony Von Leuwen Hook.

Q 9 – The disease caused by protozoa is
(a) tuberculosis
(b) polio
(c) typhoid
(d) malaria

Ans 9 –(d) malaria

Q 10 –Virus reproduce:
(a) only outside the cells of the host organisms
(b) only inside the cells of the host organisms
(c) both inside and outside the cells of the host organisms
(d) none of these

Ans 10 –(b) only inside the cells of the host organisms
Virus reproduce only inside the cells of the host organisms

Q 11 – Which cannot fix atmospheric nitrogen in the soil?
(a) Rhizobium
(b) Clostridium
(c) Azotobacter
(d) Penicillin

Ans 11 – (d) Penicillin

Q 12 –Which of the following lives alone:
(a) amoeba
(b) fungi
(c) bacteria
(d) all of these

Ans 12 –(a) amoeba
Amoeba lives alone whereas fungi and bacteria live in colonies.

Q 13 – Which microorganism causes AIDS?
(a) A protozoa
(b) A bacteria
(c) A virus
(d) An algae

Ans 13 – (c) A virus

Q 14 –Atmospheric nitrogen ¡s used for the synthesis of:
(a) plant proteins
(b) animal proteins
(c) plant carbohydrates
(d) none of these

Ans 14 – (a) plant proteins
Atmospheric nitrogen is used for the synthesis of plant proteins

Q 15 – The host for malaria-causing protozoan is:
(a) Anopheles mosquito
(b) the cow
(c) the earthworm
(d) the tapeworm

Ans15 – (a) anopheles mosquito

Q 16 – The process of conversion of sugar into alcohol is known as:
(a) pasteurization
(b) fermentation
(c) decomposition
(d) none of these

Ans 16 – (b) fermentation

Q 17 –The percentage of nitogen in the atmosphere:
(a) increases during day time
(b) decreases during day time
(c) remains more or less constant
(d) can’t say

Ans17 (c) remains more or less constant
The percentage of nitrogen in the atmosphere remains more or less constant.

Q 18 – In Pasteurisation the milk is heated to about:
(a) 100°C
(b) 50°C
(c) 70°C
(d) 110°C

Ans 18 – (c) 70°C

Q 19 –Which of the folidwing is a preservative:
(a) sodium benzoate
(b) common salt
(c) vinegar
(d) all of these

Ans19 – (d) all of these
Sodium benzoate, common salt and vinegar are all preservatives

Q 20 – The bacterium living in the root nodules of leguminous plants is:
(a) lactobacillus
(b) acetobactor
(c) Rhizobium
(d) none of these

Ans 20 – (c) Rhizobium

Q 21 –Communicable diseases are spread from an infected person to a healthy person through:
(a) air
(b) water
(c) food
(d) all of these

Ans 21 – (b) water
Communicable diseases are spread from an infected person to a healthy person through
air, water, food and physical contact.

Q 22 –Hepatitis-A is transmitted through:
(a) water
(b) air
(c) food
(d) contact

Ans 22 – (a) water

Q 23 –is the process by which alcohol and Co2 are produced by yeast cells.
(a) respiration
(b) digestion
(c) evaporation
(d) fermentation

Ans 23 – (a) respiration
Respiration is the process by which alcohol and Co2 are produced by yeast cells

Q 24 – A group of microorganisms that have the characters of both living and non-living are:
(a) bacteria
(b) protozoa
(c) virus
(d) fungi

Ans 24 – (c) virus

Q 25 –Cause of malaria is:
(a) fungi
(b) bacteria
(c) protozoa
(d) virus

Ans 25 – (c) protozoa
Protozoa called plasmodium is the cause of malaria

Q 26 – Which of the following drug is an antibiotic?
(a) Alcohol
(c) streptomycin
(b) insulin
(d) none of these

Ans 26 – (c) streptomycin

Q 27 –The algae commonly used as fertilisers are called:
(a) chlorellin
(b) blue-green algae
(c) spirogyra
(d) none of these

Ans 27 – (b) blue-green algae
Blue-green algae are used as fertilisers because they can fix atmospheric nitrogen to
usable compounds which help in crop growth and improves the water holding capacity of
soil.

Q27– Tuberculosis is a disease caused by:
(a) bacterium
(b) protozoan
(c) virus
(d) malnutrition

Ans 27– (a) bacterium

Q 28 –Virus is.
(a) non-living
(c) living as well as non-living
(b) living
(d) none of these

Ans28 – (c) living as well as non-living
Virus is living as well as non-living.

Q28–Cholera is due to:
(a) virus
(b) fungus
(c) protozoan
(d) bacterium

Ans 28 – (d) bacterium

Q 29 –Tuberculosis is a disease caused by:
(a) bacterium
(b) protozoan
(c) virus
(d) malnutrition

Ans 29 – (a) bacterium
Tuberculosis is causes by bacterium.

Q 30 – Which of the following is an air-borne disease:
(a) typhoid
(b) tuberculosis
(c) cholera
(d) polio

Ans 30 – (c) cholera

Q 31 –BCG vaccine is used to curb:
(a) cholera
(b) tuberculosis
(c) polio
(d) typhoid

Ans 31– (b) tuberculosis
BCG vaccine is used to curb tuberculosis.

Q 32 – Protozoan shaped like a slipper is:
(a) amoeba
(b) paramecium
(c) euglena
(d) entamoeba

Ans 32– (b) paramecium

Q 33 –Which of the following is air-borne disease:
(a) typhoid
(b) tuberculosis
(c) cholera
(d) polio

Ans 33 – (c) cholera
Tuberculosis is an air-borne disease.

Q 34 –The bacterium that turns milk into curd is:
(a) lactobacillus
(b) acetobacter
(c) rhizobium
(d) none of these

Ans34 – (a) lactobacillus

Q 35 –Breathing in polluted air causes:
(a) kidney trouble
(b) heart problem
(c) respiratory diseases
(d) none of these

Ans 35–(c) respiratory diseases
Breathing in polluted air causes respiratory diseases.

Q 36 –Atmospheric nitrogen is used for the synthesis of:
(a) plant proteins
(b) animal proteins
(c) plant carbohydrates
(d) none of these

Ans 36 – (a) plant proteins

Q 37–Yeast helps in the production of:
(a) sugar
(b) alcohol
(c) oxygen
(d) none of these

Ans37– (b) alcohol
Yeast helps in the production of alcohol

Q 38– The algae commonly used as fertilizers are called:
(a) chlorellin
(b) blue-green algae
(c) spirogyra
(d) none of these

Ans38 – (b) blue-green algae

Q 39 – Leprosy is caused by:
(a) bacteria
(c) virus
(b) protozoa
(d) fungi

Ans 39 – (a) bacteria

Q40 – The cause of whooping cough is
(a) bacteria
(c) virus
(b) fungi
(d) algae

Ans 40 – (a) bacteria

Q 41 – Match the Following:

Column-A	Column-B
(a) Dysentry	(i) Bacteria
(b) Chicken pox	(ii) Protozoa
(c) Tuberculosis	(iii) Fungi
(d) Athlete’s foot	(iv) Virus

Ans 41– Match the Following:

Column-A	Column-B
(a) Dysentry	(ii) Protozoa
(b) Chicken pox	(iv) Virus
(c) Tuberculosis	(i) Bacteria
(d) Athlete’s foot	(iii) Fungi