CBSE Class 8 Science Worksheet
Microorganisms: Friends or Foe
1.
Choose the correct answer: Spirogyra is a/an _________.
A)
fungi
B)
protozoa
C)
bacteria
D)
algae
2.
The gas released during the preparation of bread is
A)
Oxygen
B)
Carbon Dioxide
C)
Nitrogen
D)
Sulphur Dioxide
3.
State true or false: Mode of transmission of rust of wheat disease in plants is air and seeds.
A)
true
B)
false
4.
Choose the correct answer: Causative microorganism of malaria is _________.
A)
virus
B)
protozoa
C)
bacteria
D)
fungi
5.
Which of the following is a common preservatives?
A)
Sodium metabisulphite
B)
sodium carbonate
C)
sodium bicarbonate
D)
sodium chloride
6.
Fill in the blanks: Disease causing microorganisms are called ________________.
7.
Q8. Which microorganism has the capacity to fix atmospheric nitrogen to enrich soil?
A)
Protozoa
B)
Blue green algae
C)
Fungi
D)
Virus
8.
Fill in the blanks: Microorganisms can be seen with the help of a ____________________.
9.
In order to take precautionary steps to control dengue, we must take measures to stop the breeding of:
A)
Aedes mosquito
B)
Anopheles mosquito
C)
House Flies
D)
Ants
10.
Which of these doesn't prevent growth of bacteria?
A)
salt
B)
oil
C)
water
D)
None of these
11.
Define symbiotic relationship.
12.
Which of the following is not a communicable disease?
A)
tuberculosis
B)
chicken pox
C)
diabetes
D)
common cold
13.
Choose the correct answer: The most common carrier of communicable disease is ____________.
A)
spider
B)
housefly
C)
butterfly
D)
dragonfly
14.
All microorganisms are friendly
A)
True
B)
False
16.
Choose the correct answer: Agent which spreads pathogens from one place to another is ___________.
A)
antibody
B)
microbe
C)
vector
D)
None of these
18.
State true or false: Tuberculosis, smallpox and hepatitis can be prevented by vaccination.
A)
true
B)
false
19.
State true or false: Algae is an important ingredient when for the preparation of idli batter.
A)
true
B)
false
20.
Fill in the blanks: Our body produces __________________ to fight disease-carrying microbes.
CBSE Class 8 Science Worksheet
Microorganisms: Friends or Foe
Answers
1.
Option D
2.
Option B
3.
Option A
4.
Option B
5.
Option A
6.
pathogens
7.
Option B
8.
microscope
9.
Option A
10.
Option C
11.
It is the relationship between two organisms in which both the organisms are benefitted.
12.
Option C
13.
Option B
14.
Option B
Solution:
Microorganisms are a vast group. Some are helpful (making dairy products) while some are harmful (causes diseases)
15.
Option B
16.
Option C
17.
It is the process of heating milk to about 700C for 15 to 30 seconds and then suddenly cooling it inorder to prevent the growth of microbes.
18.
Option A
19.
Option B
20.
antibodies
