Class 8 Science Chapter 2 MCQ

Class 8 Science Chapter 2 MCQ (Multiple Choice Questions) of Microorganism: Friend and Foe. There are 25 MCQ Tests containing more than 100 questions with answers and explanation, prepared for new academic session 2020-21.

MCQ are prepared from NCERT Textbook of Class 8 Science and Exemplar book including all the best questions for practice.




Class 8 Science Chapter 2 MCQ for 2020-21

Class: 8Science
Chapter 2:MCQ Tests of Microorganism: Friend and Foe

Class 8 Science Chapter 2 MCQ Tests for Exams

Class 8 Science Chapter 2 MCQ Tests of Microorganism: Friend and Foe with complete explanation and answers. All the questions have four option with one option correct. After attempting you can see the answer and explanation for justification. All the important topics of NCERT Books 8th Science Chapter 2 have been added in these MCQs.

Q1

Consider the following sentences and choose the correct statements.

[A]. Edward Jenner is known for his role in identification of the causing agent of Anthrax.
[B]. Robert Koch discovered the vaccine for smallpox in 1798.
[C]. Louis Pasteur discovered fermentation in 1857 by demonstrating the microbes cause souring of milk.
[D]. All the above
Q2

There are some characteristics of tuberculosis patient. Choose the incorrect one:

[A]. Tuberculosis is infectious airborne disease.
[B]. We should avoid standing when the any person cough.
[C]. It is caused by lactobacillus bacteria.
[D]. All the above




Q3

Pathogenic microorganisms present in host cells are killed by medicines called

[A]. Pain killer
[B]. Antibodies
[C]. Antibiotics
[D]. Vaccines
Q4

Paheli is writing some sentences about “algae”. In which of sentences, she is writing as incorrect?

[A]. Spirogyra is single-celled algae.
[B]. Chlamydomonas and diatoms are multi-celled algae.
[C]. Blue-green algae can not fix nitrogen gas of atmosphere.
[D]. All the above.




Q5

The two microorganisms which live in symbiotic association in lichens are

[A]. Fungus and protozoa
[B]. Algae and bacteria
[C]. Bacteria and protozoa
[D]. Algae and fungus
Q6

The gas released during the preparation of bread is

[A]. Oxygen
[B]. Carbon dioxide
[C]. Nitrogen
[D]. Sulphur dioxide




Q7

Malaria is caused by

[A]. Bacteria
[B]. Virus
[C]. Fungus
[D]. None of the above.
Q8

There are given some statements. Boojho wants to know which of the following statement is or are incorrect?

[A]. Housefly carries the disease-causing microbes’ insides the body.
[B]. Mosquito carries microbes outside its body.
[C]. Ades mosquito carries the plasmodium parasite of malaria.
[D]. All the above



Q9

The precaution is observed in the use of antibiotics. Choose the incorrect sentence(s):

[A]. Antibiotic may kill the useful bacteria in the body and harm us.
[B]. Wrong dose of antibiotics makes the antibiotic less effective.
[C]. Antibiotics should be taken only on the advice of perfect doctor.
[D]. None of the above
Q10

Paheli and boojho discussed a topic of microorganisms. Choose which of the following statements is or are incorrect?

[A]. A dilute solution of Acetic acid is called vinegar.
[B]. Acetobacter bacteria convert alcohol into acetic acid.
[C]. Yeast is capable of converting sugar into alcohol.
[D]. None of the above.

Types of Fungi

Yeasts:Unicellular organisms.
Moulds:Multi cellular organisms.
Mushrooms:Multi cellular organisms.
Maldews:Unicellular organisms.



The Common Characters of Viruses
    • They are the smallest living organisms.
    • They do not have a cellular structure.
    • They have a simple structure, consisting of a small piece of Nucleic Acid (either DNA or RNA), surrounded by a protein coat.
    • They are on the boundary between living and non-living.
Discovery of Viruses

In 1852, a Russian botanist D.I. Ivanovsky discovered viruses from tobacco plants. These viruses were named as TMV (Tabacco Mosaic Viruses). Viruses are the smallest living organisms, ranging in size from about 20-300 mm on average. They cannot be seen with the simple microscope. They pass through filters which retain bacteria.

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What is micro-biology?

There is a world of living organisms which cannot be seen with the naked eyes. They can be seen only through a microscope. Microorganisms are often described as single -celled or unicellular organisms, but there are certain species that are multi-cellulars. The study of micro-organisms is called micro-biology.

What are Extremophiles?

Micro-organisms are found in a variety of places, and they can survive in extremely harsh environmental
conditions. Some types of micro-organisms have adapted to the extreme conditions and sustained colonies; these organisms are known as Extremophiles.

What is Bacteriology?

Becteria are microscopic, unicellualar organisms. They are often coocus -(Spherical) or red-shaped and 0.5- 51/m in the longest dimension. The study of bacteria is known as Bacteriology.

What are Pathogens?

Some micro-organisms are useful to us in many ways, while some are definitely harmful since they cause diseases. The microorganisms which cause disease are known as Pathogens.