Class 8 Science Microorganisms Friends and Foe

Last updated on June 28th, 2023 at 11:09 pm

NCERT Solution Class 8 Chapter 2 Microorganisms

Fill in the blanks.

 

(a) Microorganisms can be seen with the help of a _______[microscope]

(b) Blue green algae fix _______ directly from air and enhance fertility

of soil. [nitrogen]

(c) Alcohol is produced with the help of __________.[yeast]

(d) Cholera is caused by __________.[bacteria]

 

Tick the correct answer.

(a) Yeast is used in the production of

1. sugar
2. alcohol
3. hydrochloric acid
4. oxygen

alcohol

 

(b) The following is an antibiotic

1. Sodium bicarbonate
2. Streptomycin
3. Alcohol
4. Yeast

streptomycin

 

(c) Carrier of malaria-causing protozoan is

1. female Anopheles mosquito
2. cockroach
3. housefly
4. butterfly

Female anopheles mosquito

 

(d) The most common carrier of communicable diseases is

1. ant
2. housefly
3. dragonfly
4. spider

Housefly

 

(e) The bread or idli dough rises because of

1. heat
2. grinding
3. growth of yeast cells
4. kneading

Growth of yeast cells

 

(f) The process of conversion of sugar into alcohol is called……

1. nitrogen fixation
2. moulding
3. fermentation
4. infection

Fermentation