Questions and Answers
Class 8, Chapter 2 - Microorganisms: Friend and foe | NCERT
1.
Which microorganisms reproduce only inside cells of host organism?
viruses
2.
Which diseases are caused by protozoa?
dysentery, malaria
3.
Amoeba is a representative of:
Protozoa
4.
Which microorganisms may be multicellular?
algae, fungi
Which statements are true?
5.
Microorganisms are used in agriculture for fixing nitrogen.
True
6.
Fungi is used in curd production.
False
7.
Yeast produces nitrogen during respiration.
False
8.
What is fermentation?
It is a process of conversion of sugars into alcohol.
Match a scientist with his discovery
9.
Alexander Fleming
penicillin
10.
Louis Pasteur
fermentation
11.
Edward Jenner
smallpox vaccine
12.
Robert Koch
Bacillus anthracis
13.
Describe process of milk pasteurisation.
Milk is heated to about 70°C for 15 to 30 seconds and then suddenly chilled.
14.
AIDS is caused by:
a virus
15.
How do we call insects and animals that can pass a diseasce causing microbes to us?
carriers
16.
How much of the Earth's atmosphere is made up of nitrogen?
78%