Short questions in board exams usually come from these topics:

1. What is a bacterium?

Define bacterium. Describe it as a prokaryotic organism.

2. What is the difference between prokaryotic and eukaryotic cells?

Explain the main differences: nucleus, membrane-bound organelles, size, etc.

3. What is the bacterial cell wall made of?

The bacterial cell wall is made of peptidoglycan (murein).

4. What is a Gram-positive bacterium?

Describe Gram-positive bacteria. They have a thick peptidoglycan layer and stain purple.

5. What is a Gram-negative bacterium?

Describe Gram-negative bacteria. They have a thin peptidoglycan layer and an outer membrane. They stain pink/red.

6. What is an endospore?

Define endospore. Explain that it is a dormant, tough, non-reproductive structure formed by some bacteria.

7. Why do bacteria form endospores?

Bacteria form endospores to survive unfavourable conditions like high temperature, radiation, and lack of nutrients.

8. What is a bacterial flagellum?

Define flagellum. Describe it as a long, whip-like structure used for movement.

9. How do bacteria move?

Bacteria move using flagella (and sometimes by gliding or twitching).

10. What is the role of bacteria in the nitrogen cycle?

Bacteria fix atmospheric nitrogen into usable forms for plants. They also convert nitrogen back into the atmosphere.

11. What is nitrogen fixation?

Define nitrogen fixation. Explain that certain bacteria convert atmospheric nitrogen into ammonia.

12. What is Rhizobium?

Define Rhizobium. It is a bacterium that fixes nitrogen in the root nodules of leguminous plants.

13. How are bacteria useful in food production?

Bacteria are used to produce yogurt, cheese, pickles, and other fermented foods.

14. What are antibiotics?

Define antibiotics. Explain that they are substances produced by microorganisms that kill or inhibit bacteria.

15. What is normal flora?

Define normal flora. Explain that they are microorganisms that live on and inside the human body without causing disease.

16. What are the benefits of normal flora?

Explain the benefits: digestion, vitamin production, prevention of harmful bacteria, immune system stimulation.

17. What is a bacteriophage?

Define bacteriophage. Describe it as a virus that infects bacteria.

18. What is HIV?

Define HIV. Describe it as the human immunodeficiency virus that causes AIDS.

19. What is the structure of HIV?

Describe the structure: outer envelope, glycoprotein spikes, capsid, reverse transcriptase, RNA.

20. What is the role of bacteria in sewage treatment?

Bacteria decompose organic matter in sewage, making it safe for disposal.