Bacteria Quiz - CBSE Class 8 Science

Free practice quiz: Bacteria (CBSE Class 8 Science). 20 multiple-choice questions with answers and explanations. Play online, no sign-up needed.

This CBSE Class 8 Science practice quiz has 20 multiple-choice questions on Bacteria, and 20 of them come with an explanation. Try the 5 sample questions below (tap an option to check yourself), then play the full quiz online. No sign-up needed.

Sample questions

1. What shape do most bacteria have?

   1. Spherical
   2. Square
   3. Triangular
   4. Pentagonal
   Show answer

   Answer: A. Spherical

   Most bacteria are spherical in shape, also known as cocci.

2. Which type of bacteria stain purple in the Gram stain procedure?

   1. Gram-positive
   2. Gram-negative
   3. Mycobacteria
   4. Spirilla
   Show answer

   Answer: A. Gram-positive

   Gram-positive bacteria take up the crystal violet dye and appear purple when stained.

3. What characteristic distinguishes archaea from bacteria?

   1. Presence of a nucleus
   2. Different cell wall composition
   3. Isolation methods
   4. Reproduction rates
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   Answer: B. Different cell wall composition

   Archaea have distinct cell wall compositions made up of proteins and polysaccharides.

4. What type of bacteria are pathogens?

   1. Beneficial bacteria
   2. Harmful bacteria
   3. Neutral bacteria
   4. Saprophytic bacteria
   Show answer

   Answer: B. Harmful bacteria

   Pathogens are harmful bacteria that can cause disease in hosts.

5. What are biofilms?

   1. Colonies of different bacterial species
   2. Negative bacteria
   3. Single-celled bacteria
   4. Viruses
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   Answer: A. Colonies of different bacterial species

   Biofilms are dense clusters of microbial cells that adhere to surfaces, often involving various species.

More questions in this quiz

Answers and explanations are in the full quiz.

1. What is the primary component of bacterial cell walls?
2. What is the term for bacteria that can survive without oxygen?
3. Which bacterial reproduction method involves doubling the genetic material?
4. Which bacteria are known for their role in nitrogen fixation?
5. What is a common use of bacteria in food production?
6. What is a bacteriophage?
7. Which of the following is NOT true about bacteria?
8. What is antibiotic resistance in bacteria?
9. Which of the following techniques is used to identify bacteria?
10. How do bacteria contribute to soil fertility?
11. What is the role of plasmids in bacteria?
12. Which staining technique is most commonly used in microbiology?
13. How does temperature affect bacterial growth?
14. What is horizontal gene transfer?
15. Which of the following diseases is caused by bacteria?

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