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Practice Class 8 Science Chapter 2 Microorganisms: Friend and Foe MCQ Questions with Answers and Useful Details based on the NCERT syllabus. Revise plant diseases, animal diseases, human diseases, disease-causing microorganisms, and methods of disease prevention.
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Chapter Information
Subject: Science
Class: 8
Chapter: Microorganisms: Friend and Foe
Question Type: Multiple Choice Questions (MCQs)
Practice Set: 8
Difficulty Level: Moderate to Difficult
Based On: NCERT Syllabus
Introduction
Microorganisms are present in almost every environment and can interact with humans, animals, and plants. While many microorganisms are useful, some act as pathogens and cause diseases.
Diseases caused by microorganisms can affect humans, animals, and plants. They may spread through air, contaminated food and water, direct contact, or carriers such as insects.
Understanding the causes and modes of transmission of diseases is important for preventing infections and protecting health.
This Practice Set 8 focuses on diseases caused by microorganisms in humans, animals, and plants, along with their methods of transmission and prevention.
What You Will Learn
✔ Pathogens
✔ Human diseases caused by microorganisms
✔ Animal diseases
✔ Plant diseases
✔ Disease transmission
✔ Airborne diseases
✔ Waterborne diseases
✔ Vector-borne diseases
✔ Disease prevention
✔ Importance of hygiene
Why This Topic Is Important
Microbial diseases can affect the health of individuals, animals, and crops. Some diseases spread quickly when proper hygiene and sanitation are not maintained.
Farmers also need to understand plant diseases because microorganisms can damage crops and reduce agricultural production.
Learning about disease-causing microorganisms helps students understand the importance of clean water, sanitation, hygiene, vaccination, food safety, and protection from disease vectors.
5 MCQs with Answers and Useful Details
Q1. Which microorganism causes tuberculosis?
A) Bacterium
B) Virus
C) Fungus
D) Alga
Answer:
A) Bacterium
Useful Detail
Tuberculosis (TB) is caused by a bacterium called Mycobacterium tuberculosis.
It mainly affects the lungs and can spread through the air when an infected person coughs or sneezes.
Good ventilation, early diagnosis, appropriate treatment, and public-health measures help control the spread of tuberculosis.
Correct Answer: A) Bacterium
Q2. Which disease is caused by a virus?
A) Polio
B) Cholera
C) Tuberculosis
D) Typhoid
Answer:
A) Polio
Useful Detail
Polio is caused by a virus called poliovirus.
It is a communicable disease that can spread from one person to another, particularly through contaminated food or water in settings with poor sanitation.
Vaccination is an important method of preventing polio and has played a major role in controlling the disease.
Correct Answer: A) Polio
Q3. Which disease affects plants and is caused by a bacterium?
A) Citrus canker
B) Malaria
C) Tuberculosis
D) Polio
Answer:
A) Citrus canker
Useful Detail
Citrus canker is a bacterial disease that affects citrus plants such as lemon and orange.
It causes characteristic lesions on the leaves, stems, and fruits of infected plants.
Plant diseases caused by microorganisms can reduce crop quality and production, making their prevention important for agriculture.
Correct Answer: A) Citrus canker
Q4. Which disease is caused by a fungus and commonly affects wheat plants?
A) Rust of wheat
B) Polio
C) Cholera
D) Malaria
Answer:
A) Rust of wheat
Useful Detail
Rust of wheat is a fungal disease that affects wheat plants.
Fungal diseases can damage leaves and other plant parts and may reduce crop yield.
Recognising plant diseases early helps farmers take suitable preventive and control measures.
Correct Answer: A) Rust of wheat
Q5. Which method is most useful for reducing the spread of diseases caused by contaminated water?
A) Drinking untreated water
B) Using safe and properly treated drinking water
C) Leaving water containers uncovered
D) Storing water in dirty containers
Answer:
B) Using safe and properly treated drinking water
Useful Detail
Diseases such as cholera and typhoid can spread through contaminated food and water.
Using safe drinking water, maintaining sanitation, washing hands, and ensuring hygienic food preparation can reduce the risk of such infections.
Proper treatment and storage of drinking water are especially important in preventing waterborne diseases.
Correct Answer: B) Using safe and properly treated drinking water
Important Formulas & Concepts
Science Chapter 2 does not contain mathematical formulas. Important scientific concepts are given below.
1. Pathogens
Disease-causing microorganisms are called pathogens.
2. Tuberculosis
Tuberculosis is a bacterial disease that mainly affects the lungs and can spread through air.
3. Polio
Polio is a viral disease that can spread through contaminated food and water.
4. Citrus Canker
Citrus canker is a bacterial disease affecting citrus plants.
5. Rust of Wheat
Rust of wheat is a fungal disease that affects wheat plants.
6. Waterborne Diseases
Diseases that can spread through contaminated water include cholera and typhoid.
7. Airborne Diseases
Some diseases can spread through infected droplets or particles in the air, such as tuberculosis and the common cold.
8. Vector-Borne Diseases
Some diseases are transmitted by carriers such as mosquitoes. Malaria is an example.
9. Plant Diseases
Microorganisms such as bacteria, fungi, and viruses can cause diseases in plants.
10. Disease Prevention
Safe water, sanitation, hygiene, vaccination, food safety, and vector control can help prevent many infectious diseases.
Related Practice Questions
Q1. What causes tuberculosis?
Q2. Which microorganism causes polio?
Q3. What is citrus canker?
Q4. What causes rust of wheat?
Q5. How can waterborne diseases be prevented?
Mini Quiz Challenge
Try answering these questions within 60 seconds.
Q1. Tuberculosis is caused by:
A) Bacteria
B) Virus
C) Fungus
D) Algae
Q2. Polio is caused by:
A) Virus
B) Bacterium
C) Fungus
D) Protozoan
Q3. Citrus canker affects:
A) Citrus plants
B) Wheat plants
C) Potato plants only
D) Rice plants only
Q4. Rust of wheat is caused by:
A) Fungus
B) Virus
C) Bacterium
D) Protozoan
Q5. Which is important for preventing waterborne diseases?
A) Safe drinking water
B) Contaminated water
C) Poor sanitation
D) Uncovered waste
Exam Tips
✔ Remember the causative type of microorganism for important diseases.
✔ Learn that tuberculosis is caused by a bacterium.
✔ Remember that polio is caused by a virus.
✔ Learn citrus canker as a bacterial plant disease.
✔ Remember rust of wheat as a fungal disease.
✔ Revise examples of airborne, waterborne, and vector-borne diseases.
✔ Learn the importance of safe drinking water.
✔ Remember that mosquitoes can act as disease vectors.
✔ Do not confuse the disease with its mode of transmission.
✔ Revise plant diseases along with human diseases.
Quick Revision Notes
✔ Tuberculosis: Bacterial disease; mainly affects the lungs.
✔ Polio: Viral disease.
✔ Citrus Canker: Bacterial disease of citrus plants.
✔ Rust of Wheat: Fungal disease of wheat.
✔ Cholera: Can spread through contaminated food and water.
✔ Typhoid: Can spread through contaminated food and water.
✔ Malaria: Caused by Plasmodium and transmitted by infected female Anopheles mosquitoes.
✔ Airborne Transmission: Spread through infected droplets or particles.
✔ Waterborne Transmission: Spread through contaminated water.
✔ Vector-Borne Transmission: Spread through carriers such as mosquitoes.
Common Mistakes Students Make
❌ Thinking tuberculosis is caused by a virus.
❌ Confusing polio with bacterial diseases.
❌ Forgetting that citrus canker is a plant disease.
❌ Confusing rust of wheat with rust-like chemical corrosion.
❌ Thinking every disease spreads through the same route.
❌ Forgetting that contaminated water can transmit diseases.
❌ Confusing a disease-causing organism with its vector.
❌ Thinking plant diseases cannot be caused by microorganisms.
Key Takeaways
✔ Microorganisms can cause diseases in humans, animals, and plants.
✔ Tuberculosis is a bacterial disease.
✔ Polio is caused by a virus.
✔ Citrus canker is a bacterial plant disease.
✔ Rust of wheat is a fungal disease.
✔ Some diseases spread through air.
✔ Some diseases spread through contaminated food and water.
✔ Some diseases are transmitted by vectors.
✔ Hygiene, sanitation, safe water, vaccination, and vector control help prevent many infectious diseases.
FAQs
Q. What causes tuberculosis?
Answer:
Tuberculosis is caused by the bacterium Mycobacterium tuberculosis and mainly affects the lungs.
Q. Is polio caused by a bacterium?
Answer:
No. Polio is caused by a virus called poliovirus.
Q. What is citrus canker?
Answer:
Citrus canker is a bacterial disease that affects citrus plants such as lemon and orange.
Q. What causes rust of wheat?
Answer:
Rust of wheat is caused by a fungus that infects wheat plants.
Q. How can waterborne diseases be prevented?
Answer:
Waterborne diseases can be reduced by using safe drinking water, maintaining proper sanitation, washing hands, and following hygienic food preparation and storage practices.
Conclusion
Class 8 Science Chapter 2 – Microorganisms: Friend and Foe focuses on diseases caused by microorganisms in humans and plants.
Students revised tuberculosis, polio, citrus canker, rust of wheat, waterborne diseases, airborne diseases, vector-borne diseases, and disease prevention.
Understanding the causative microorganisms and transmission routes helps students answer conceptual questions and understand the importance of hygiene, sanitation, vaccination, and safe water.
Related links
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- Class 8 Science Chapter 2 Microorganisms Friend and Foe part-7
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- Class 8 English Chapter 2 A Concrete Example part-4
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- Class 8 Science Chapter 2 Microorganisms Friend and Foe part-6
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- Class 8 Science Chapter 2 Microorganisms Friend and Foe part-5
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