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Environment and Biodiversity MCQs – 06 ( Environmental Pollution and Climate Change)

Most important MCQs from the chapter – Environmental Pollution and Climate Change MCQs for UPSC, State PSC and Other Examinations.

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1. Consider the following statements about primary and secondary pollutants:

1. A primary pollutant is an air pollutant emitted directly from a source unlike a secondary pollutant.
2. A primary pollutant has a much shorter life in the atmosphere than a secondary pollutant.

Which of the above is/are correct?

(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

Answer with detailed explanation

Correct Answer – (a) 1 only

A primary pollutant is an air pollutant emitted directly from a source.
A secondary pollutant is not directly emitted but forms when primary pollutants react in the atmosphere with other components
Example of primary pollutants → Carbon monoxide(Emitted from a vehicle’s exhaust, nitrogen oxides and sulfur oxide etc.
Examples of a secondary pollutant → Ozone (Formed when hydrocarbons and nitrogen oxides (NOx) combine in the presence of sunlight), Acid rain (Formed when sulfur/nitrogen oxides react with rain water).
A secondary pollutant has a much shorter life in the atmosphere than a primary pollutant.

2. Which of the following is not a greenhouse gas ?

(a) Nitrogen
(b) Methane
(c) Nitrous oxide
(d) Carbon dioxide

Answer with detailed explanation

Correct Answer – (a) Nitrogen

Nitrogen is not a Greenhouse gas.
It is not responsible for increasing the global temperature.

3. Photochemical smog does NOT consist of which among the following ?

(a) Sulfur oxides
(b) Tropospheric ozone
(c) Volatile organic compounds
(d) Nitrogen oxides

Answer with detailed explanation

Correct Answer – (a) 1 only

Photochemical smog is the chemical reaction of sunlight, nitrogen oxides and volatile organic compounds in the atmosphere, which leads to the formation of ground-level ozone also called Tropospheric ozone.
Photochemical smog is most common in the summer.

4. Consider the following statements about fly ash:

1. It is a byproduct of burning coal in power plants.
2. It hardens when mixed with water.

Which of the above is/are correct?

(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

Answer with detailed explanation

Correct Answer – (c) Both 1 and 2

Fly ash is a fine, powdery material that’s a byproduct of burning coal in power plants.
It hardens when mixed with water or an alkaline substance like lime. This makes it useful as a replacement for cement in concrete and other building materials.
It is also used in road construction.

5. Coastal erosion is reduced by:

(1) Global warming induced sea level rise
(2) Presence of coral reefs
(3) Growth of mangroves near the seashore

Select the correct answer using the codes below.

(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) All of the above

Answer with detailed explanation

Correct Answer – (a) 1 and 2 only

Global warming induced sea level rise increases coastal erosion.
Presence of coral reefs and growth of mangroves near the seashore help in controlling the coastal erosion.

6. Consider the following statements about Black carbon:

1. It is formed due to incomplete combustion of fossil fuels.
2. It is short-lived in the atmosphere in comparison to carbon dioxide.

Which of the above is/are correct?

(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

Answer with detailed explanation

Correct Answer – (c) Both 1 and 2

Black Carbon (BC) is a short-lived pollutant that is a major cause of global warming.
It is formed due to incomplete combustion of fossil fuels, biofuel, and biomass.

7. Which one of the following is the most abundant greenhouse gas in the atmosphere ?

(a) Carbon dioxide
(b) Methane
(c) Ozone
(d) Water vapor

Answer with detailed explanation

Correct Answer – (d) Water vapor

Water vapor (H2O) is the most abundant and most potent greenhouse gas in the atmosphere.
The amount of water vapor in the atmosphere is dependent on temperature.
The warmer the surface, the greater the rate of evaporation of water from the surface → Increased evaporation leads to a greater concentration of water vapor in the lower atmosphere capable of absorbing more infrared radiation and increasing the temperature further.
Other major greenhouse gasses are:
- Carbon dioxide (CO2)
- Nitrous oxide (N2O)
- Methane (CH4)
- Ozone (O3)

8. Climate change is caused by which among the following ?

(a) Increased greenhouse gasses
(b) Depletion of ozone layer
(c) Pollution
(d) All the above

Answer with detailed explanation

Correct Answer – (d) All the above

Increased greenhouse gasses, Ozone layer depletion, pollution, Cutting down forests are all responsible for climate change.

9. The Ozone layer restricts which among the following rays ?

(a) Visible light
(b) Infrared radiation
(c) X-rays and Gamma rays
(d) Ultraviolet radiation

Answer with detailed explanation

Correct Answer – (d) Ultraviolet radiation

The Ozone layer restricts the harmful Ultraviolet radiation (UV rays).
Overexposure to UV rays can cause sunburn and skin cancer hence Ozone layer depletion is a major concern.

10. Which of the following gasses is released from rice fields in large quantities ?

(a) Carbon monoxide
(b) Methane
(c) Carbon dioxide
(d) Sulphur dioxide

Answer with detailed explanation

Correct Answer – (b) Methane

Anaerobic decomposition of organic material in flooded rice fields produces large quantities of methane.
It is to be noted that Methane is one of the major greenhouse gasses.

11. Consider the following statements about Persistent Organic Pollutants (POPs):

1. They remain in the environment for long periods.
2. They can accumulate in the fatty tissue of humans and wildlife.

Which of the above is/are correct?

(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

Answer with detailed explanation

Correct Answer – (c) Both 1 and 2

Persistent Organic Pollutants(POPs) are chemical substances that have following properties:
- They can remain in the environment for long periods.
- They can accumulate in the fatty tissue of humans and wildlife.
- They are less soluble in water.
- They are harmful for human health and the environment.
The Stockholm Convention on Persistent Organic Pollutants (POPs) is a global treaty that aims to protect the environment from the harmful effects of POPs.

12. Which of the following are the results of global warming?

1. Melting of glaciers
2. Lowering down of sea level
3. Changes in weather condition

Which of the above is/are correct?

(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) All of the above

Answer with detailed explanation

Correct Answer – (c) 1 and 3 only

Melting of glaciers, Changes in weather conditions and rise of sea level are some of the consequences of global warming.
Global warming does not cause lowering of sea level.

13. Consider the following statements about coral bleaching :

1. In coral bleaching, zooxanthellae leave coral tissues causing the coral to turn white.
2. This is caused due to pollution and sea temperature rise.

Which of the above is/are correct?

(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

Answer with detailed explanation

Correct Answer – (c) Both 1 and 2

In coral bleaching, zooxanthellae leave coral tissues causing the coral to turn white.
This is caused due to pollution and sea temperature rise.
This indicates that corals are in stress and can die if not protected.

14. Which among the following is the major underground water pollutant ?

(a) Bacteria
(b) Algae
(c) Arsenic
(d) Viruses

Answer with detailed explanation

Correct Answer – (c) Arsenic

Arsenic is a toxic, naturally occurring, semi metallic element.
Arsenic pollution of groundwater is a global issue that can pose serious health risks.
Arsenic can enter groundwater through natural processes, such as weathering of rocks and minerals, or through human activities, such as industrial processes and coal-fired power plants.
Long-term exposure to arsenic in drinking water can lead to cancer, skin lesions, cardiovascular disease, diabetes, and other health problems.

15. Acid rain is caused due to air pollution by which among the following ?

(a) Carbon dioxide
(b) Carbon monoxide
(c) Methane
(d) Nitrous Oxide and Sulfur Dioxide

Answer with detailed explanation

Correct Answer – (d) Nitrous Oxide and Sulfur Dioxide

Acid rain is caused mainly due to the presence of sulfur dioxide and nitrogen oxides in the atmosphere.
Nitrous Oxide and Sulfur Dioxide combine with water to produce sulfuric acid and nitric acid respectively.

A complete ecosystem for UPSC Civils and State PSC Preparation

Environment and Biodiversity MCQs – 06 ( Environmental Pollution and Climate Change)

Chapterwise MCQs

Short Notes

Free Test Series

CivilsCracker Explains

Also Read in Environment and Ecology MCQs :

Environment and Biodiversity MCQs – 01 ( Basics of Ecology )

Environment and Biodiversity MCQs – 02 ( Ecological succession and Forests )

Environment and Biodiversity MCQs – 03 ( Ecosystems and Biomes )

Environment and Biodiversity MCQs – 04 ( Nutrient cycles )

Environment and Biodiversity MCQs – 05 ( Environmental Conventions and Protocols )

Environment and Biodiversity MCQs – 07 (Endangered Species of India)

Environment and Biodiversity MCQs – 08 (Biodiversity Conservation)

Environment and Biodiversity MCQs – 09 (Environment Protection Initiatives in India)

Environment and Biodiversity MCQs – 10 (Environmental Organizations in India)

Environment and Biodiversity MCQs – 11 (National Parks and Tiger Reserves in India)

Environment and Biodiversity MCQs – 12 (Environment Related Days of the Year)

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