Class 8 Microorganisms Friend And Foe CBSE Questions & Answers

Class 8 · Microorganisms Friend And Foe

This is Science Class 8 Microorganisms Friend And Foe CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
A pathogenic microorganism :
  • A
    causes dryness
  • B
    carries disease causing organism
  • C
    causes disease
    Correct
  • D
    fixes nitrogen
2
Microorganisms cannot be seen by naked eyes because :
  • A
    they are ubiquitous in nature
  • B
    they are small in size
    Correct
  • C
    they are colonial
  • D
    they are unicellular
3
Viruses are living only :
  • A
    outside soil top layer
  • B
    inside host cell
    Correct
  • C
    inside water body
  • D
    outside host body
4
Microorganisms are found at every place because:
  • A
    they can form a cyst
    Correct
  • B
    they can do photosynthesis
  • C
    they can cause diseases
  • D
    they can fix nitrogen
5
Within a host cell, virus can:
  • A
    form cyst
  • B
    produce antibiotic
  • C
    reproduce
    Correct
  • D
    produce vaccine
6
An organism which can be seen only under electron microscope is :
  • A
    unicellular fungi
  • B
    single celled algae
  • C
    virus
    Correct
  • D
    bacteria
7
Virus particles come out of host cell when :
  • A
    conditions are favourable
  • B
    conditions are unfavourable
  • C
    host cell bursts
    Correct
  • D
    host cell is ready to divide
8
Which of the following microorganisms can be polygonal in shape?
  • A
    fungi
  • B
    bacteria
  • C
    viruses
    Correct
  • D
    algae
9
We study about microorganisms to :
  • A
    create database for future generations
  • B
    develop strategies to kill them and make earth disease free
  • C
    be aware of their positive and negative effects
    Correct
  • D
    increase our knowledge about science
10
Which of the following never possess flagella to move?
  • A
    Trypanosoma
  • B
    spiral bacteria
  • C
    Euglena
  • D
    virus
    Correct
11
Which of the following milk will be best for bacterial growth?
  • A
    hot milk
  • B
    powered milk
  • C
    warm milk
    Correct
  • D
    cold milk
12
Decomposers increase soil productivity by adding to it?
  • A
    heumus
  • B
    humis
  • C
    humus
    Correct
  • D
    humas
13
If a useful bacterium is living in human intestine it will:
  • A
    add antibiotics to digested food
  • B
    help in food digestion
    Correct
  • C
    help in movement of food
  • D
    help in removal of harmful microbes
14
Growth of moulds on food can make food :
  • A
    unfit for consumption
    Correct
  • B
    porous and tasty
  • C
    spongy and tasty
  • D
    good for health & tasty
15
A slipper shaped fresh water protozoan moves with the help of :
  • A
    pseudopodia
  • B
    cilia
    Correct
  • C
    tentacles
  • D
    flagella