Class 12 Biology Environmental Issue MCQs with Answers

In Class 12 Biology, Environmental Issues Multiple Choice Questions (MCQs) serve as vital tools for understanding complex ecological concepts.

These MCQs delve into topics like biodiversity loss, climate change, pollution, and conservation, fostering critical thinking and environmental awareness among students. Through structured classes, students explore the interconnections between human activities and the environment, analyzing the impact of deforestation, habitat destruction, and overexploitation of resources.

MCQs challenge students to apply theoretical knowledge to real-world scenarios, encouraging them to develop solutions for environmental sustainability. These classes also emphasize the importance of global cooperation and individual responsibility in addressing environmental issues.

By engaging with MCQs, students cultivate a deeper understanding of ecological systems, preparing them to become informed stewards of the planet.

Q1. Which of the following causes biomagnification?

1. SO₂
2. Mercury.
3. DDT.
4. Both (b) and (c).

Q2. Characteristic algal growth and water bloom are usually caused by:

1. Red algal.
2. Brown algal.
3. Blue green and green algal.
4. Bacteria.

Q3. Good ozone is found in the:

1. Stratosphere.
2. Troposphere.
3. Mesosphere.
4. Ionosphere.

Q4. Non-biodegradable pollutants are created by:

1. Nature.
2. Excessive use of resources.
3. Humans.
4. Natural disasters.

Q5. Which one of the following diseases is not due to contamination of water?

1. Hepatitis-B
2. Jaundice
3. Cholera
4. Typhoid

Q6. Which one of the following impurities is easiest to remove from wastewater?

1. Bacteria.
2. Colloids.
3. Dissolved solids.
4. Suspended solids.

Q7. The material generally used for sound proofing of rooms like a recording studio and auditorium, etc. is:

1. Cotton.
2. Coir.
3. Wood.
4. Styro foam.

Q8. Compressed Natural Gas (CNG) is:

1. Propane
2. Methane
3. Ethane
4. Butane

Q9. The thickness of ozone is measured as:

1. Parts per billion.
2. Dobson units.
3. Parts per million.
4. Decibel.

Q10. The major source of noise pollution, world wide is due to:

1. Office equipment.
2. Transport system.
3. Sugar, textile and paper industries.
4. Oil refineries and thermal power plants.

Q11. In the textbook you came across Three Mile Island and Chernobyl disasters associated with accidental leakage of
radioactive wastes. In India we had Bhopal gas tragedy. It is associated with which of the following?

1. CO₂
2. Methyl Iso-Cyanate
3. CFC’s
4. Methy Cyanat

Q12. Eutrophication causes a/ an:

1. Decrease in organic matter.
2. Increase in inorganic nutrients.
3. Decrease in dissolved oxygen.
4. Increase in dissolved oxygen.

Q13. Algal blooms impart a distinct colour to water due to:

1. Their pigments.
2. Excretion of coloured substances.
3. Formation of coloured chemicals in water facilitated by physiological degradation of algae.
4. Absorption of light by algal cell wall.

Q14. Why is it necessary to remove sulphur from petroleum products?

1. To reduce the emission of sulphur dioxide in exhaust fumes.
2. To increase efficiency of automobiles engines.
3. To use sulphur removed from petroleum for commercial purposes.
4. To increase the life span of engine silencers.

Q15. Electrostatic precipitator is employed to remove:

1. Gaseous pollutants.
2. Aerosol pollutants.
3. Particulate matter.
4. Electronic particles.

Q16. The loudness of a sound that a person can withstand without discomfort is about:

1. 150 dB.
2. 215 dB.
3. 30 dB.
4. 80 dB.

Q17. Polyblend was first developed by:

1. Ramesh Chandra Dagar.
2. Ahmed Khan.
3. Khadi and Village Industries Commission.
4. Indian Institute of Science

Q18. Increase in the concentration of pollutants/ chemicals in higher trophic levels, is known as:

1. Biodegradation.
2. Eutrophication.
3. Greenhouse effect.
4. Biomagnification.

Q19. Catalytic converters are fitted into automobiles to reduce emission of harmful gases. Catalytic converters change
unburnt hydrocarbons into:

1. Carbon dioxide and water.
2. Carbon mono oxide.
3. Methane.
4. Carbon dioxide and methane.

Q20. Increase in cases of skin cancer and high mutation rate are the result of:

1. Ozone depletion.
2. Acid rain.
3. CO₂ pollution.
4. CO₂ pollution