📖 Chapter Overview
Microorganisms are living organisms so small that they can only be seen through a microscope. They include bacteria, fungi, protozoa, algae, and viruses. Some microorganisms are beneficial, while others are harmful.
🔑 Key Points
- Types of Microorganisms: Bacteria, Fungi, Protozoa, Algae, Viruses.
- Useful Roles: Food production, medicines, nitrogen fixation, decomposition.
- Harmful Roles: Disease-causing, food spoilage, crop damage.
- Preservation Methods: Refrigeration, pasteurization, dehydration, salting.
- Examples of Diseases: Tuberculosis, Cholera, Malaria, AIDS.
📊 Table: Microorganisms and Their Uses
| Microorganism | Use | Example |
|---|---|---|
| Bacteria | Curd making | Lactobacillus |
| Fungi | Antibiotic production | Penicillium |
| Protozoa | Scientific research | Paramecium |
| Algae | Biofertilizer | Blue-green algae |
| Virus | Vaccine preparation | Polio virus (inactivated) |
📚 30 Important Questions & Answers
Q1. What are microorganisms?
Living organisms that can only be seen with a microscope.
Q2. Name five types of microorganisms.
Bacteria, fungi, protozoa, algae, viruses.
Q3. Which bacteria convert milk into curd?
Lactobacillus.
Q4. Name a protozoan disease.
Malaria (caused by Plasmodium).
Q5. Which bacterium causes tuberculosis?
Mycobacterium tuberculosis.
Q6. Name two useful fungi.
Yeast, Penicillium.
Q7. What is pasteurization?
Heating milk to kill harmful microorganisms.
Q8. Which microorganism produces alcohol?
Yeast.
Q9. Name a bacterial plant disease.
Citrus canker.
Q10. Give two viral diseases in humans.
COVID-19, Influenza.
Q11. Which bacteria fix nitrogen?
Rhizobium.
Q12. What are antibiotics?
Medicines obtained from microorganisms.
Q13. Who discovered penicillin?
Alexander Fleming.
Q14. Name a water-borne disease.
Cholera.
Q15. How to prevent food spoilage?
By salting, drying, refrigeration, pasteurization.
Q16. What are pathogens?
Disease-causing microorganisms.
Q17. Which protozoan causes dysentery?
Entamoeba histolytica.
Q18. Which virus causes AIDS?
HIV.
Q19. Example of algae.
Chlamydomonas.
Q20. What is fermentation?
Conversion of sugar into alcohol by yeast.
Q21. How do microorganisms clean the environment?
By decomposing waste.
Q22. Which fungus produces antibiotics?
Penicillium.
Q23. Name a fungal human disease.
Ringworm.
Q24. Which bacterium causes leprosy?
Mycobacterium leprae.
Q25. Which virus causes polio?
Poliovirus.
Q26. Which bacterium makes vinegar?
Acetobacter aceti.
Q27. Name a fungal plant disease.
Rust of wheat.
Q28. What is vaccination?
Introducing dead or weakened microbes to build immunity.
Q29. Name a protozoan disease in animals.
Trypanosomiasis.
Q30. Why are viruses different from other microorganisms?
They reproduce only inside host cells.