Environmental Studies Multiple Choice Questions (MCQs) with Answers

1. Which of the following is a nonrenewable source of energy?

1. Solar energy
2. Wind energy
3. Coal
4. Biomass

Answer: C Coal

Coal is a fossil fuel formed over millions of years and cannot be replenished on a human time scale.

2. The carbon footprint of an individual is measured in:

1. Litres of water used
2. Kilograms of CO equivalent
3. Number of trees planted
4. Hours of energy saved

Answer: B Kilograms of CO equivalent

A carbon footprint quantifies the total greenhouse gases emitted directly or indirectly, expressed as CO equivalents.

3. Which layer of the atmosphere contains the ozone layer?

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

Answer: B Stratosphere

The ozone layer, which absorbs most of the Suns UVB radiation, is located in the lower stratosphere.

4. A keystone species is one that:

1. Has the largest population in an ecosystem
2. Provides food for most other species
3. Has a disproportionate effect on its environment relative to its abundance
4. Is endangered

Answer: C Has a disproportionate effect on its environment relative to its abundance

Removing a keystone species can cause dramatic changes in ecosystem structure.

5. Which of the following is an example of an invasive species?

1. Native oak tree
2. American bullfrog introduced in Europe
3. Indigenous honey bee
4. Locally adapted wheat variety

Answer: B American bullfrog introduced in Europe

Invasive species are nonnative organisms that spread rapidly and cause ecological or economic harm.

6. The term edge effect refers to:

1. Changes in microclimate at the boundary of two habitats
2. Increased sunlight in forest interiors
3. Higher productivity in deep ocean zones
4. Loss of species due to fragmentation

Answer: A Changes in microclimate at the boundary of two habitats

Edges often have different temperature, humidity, and light conditions, influencing species composition.

7. Which of the following is a primary cause of eutrophication in freshwater lakes?

1. Acid rain
2. Phosphorus from agricultural runoff
3. Oil spills
4. Thermal pollution

Answer: B Phosphorus from agricultural runoff

Excess nutrients, especially phosphorus, promote algal blooms that deplete oxygen.

8. The 7 Rs of solidwaste management include Refuse, Reduce, . Which two complete the list?

1. Recycle and Recover
2. Reuse and Recycle
3. Repair and Repurpose
4. Renew and Reuse

Answer: B Reuse and Recycle

The complete 7 Rs are: Refuse, Reduce, Reuse, Recycle, Recover, Repair, and Remanufacture.

9. Which air pollutant is most directly linked to acid rain?

1. Carbon monoxide (CO)
2. Sulphur dioxide (SO)
3. Ozone (O)
4. Methane (CH)

Answer: B Sulphur dioxide (SO)

SO reacts with water vapor to form sulfuric acid, a major component of acid rain.

10. The greenhouse gas with the highest global warming potential (GWP) over a 100year horizon is:

1. Methane (CH)
2. Nitrous oxide (NO)
3. Carbon dioxide (CO)
4. Sulphur hexafluoride (SF)

Answer: D Sulphur hexafluoride (SF)

SF has a GWP of about 23,500 times that of CO over 100 years.

11. Which of the following is NOT a climatemitigation strategy?

1. Afforestation
2. Carbon capture and storage
3. Increasing fossilfuel consumption
4. Improving energy efficiency

Answer: C Increasing fossilfuel consumption

Mitigation aims to reduce greenhousegas emissions; increasing fossilfuel use would worsen the problem.

12. The term climate resilience most accurately describes:

1. The ability of a system to return to its original state after a disturbance
2. The capacity to adapt to climate impacts while maintaining essential functions
3. The speed at which greenhouse gases are removed from the atmosphere
4. The rate of sealevel rise in coastal areas

Answer: B The capacity to adapt to climate impacts while maintaining essential functions

Resilience emphasizes adaptation and continuity, not just recovery.

13. Which Sustainable Development Goal (SDG) focuses specifically on clean water and sanitation?

1. SDG 3
2. SDG 6
3. SDG 7
4. SDG 12

Answer: B SDG 6

SDG 6 aims to ensure availability and sustainable management of water and sanitation for all.

14. The concept of circular economy primarily seeks to:

1. Increase production speed
2. Minimize waste through reuse, recycling, and redesign
3. Expand the extraction of raw materials
4. Shift all manufacturing to developing nations

Answer: B Minimize waste through reuse, recycling, and redesign

A circular economy closes resource loops, reducing the need for virgin inputs.

15. Which practice best illustrates sustainable agriculture?

1. Monoculture of highyield wheat
2. Use of synthetic fertilizers exclusively
3. Integrated pest management combined with crop rotation
4. Clearing forest land for new fields

Answer: C Integrated pest management combined with crop rotation

These methods maintain soil health, reduce chemical inputs, and enhance biodiversity.