This set of Pollution Control Multiple Choice Questions & Answers (MCQs) focuses on “Effects of Pollution on Ecosystem”.
1. How is bio-amplification in the food chain defined?
a) The concentration of toxins increases with the trophic levels
b) The concentration of toxins decreases with trophic levels
c) The concentration of toxins remains the same across the trophic levels
d) The concentration of toxins changes with the trophic levels
View Answer
Explanation: Bio-amplification is defined as the increase of toxin concentration as it moves upwards in the food chain. There are two ways this can happen. First, an organism at a higher trophic level can consume the toxin from the environment. Second, the organism can accumulate it upon consumption of an organism at a lower trophic level.
2. What is the purpose of the enrichment factor?
a) It is used to calculate the rate of air contamination
b) It is used to calculate the rate of soil contamination
c) It is used to calculate the rate of water contamination
d) It is used to calculate the rate of dust contamination
View Answer
Explanation: The enrichment factor is an index used to calculate the rate of contamination of the soil. It detects the level of enrichment of a particular contaminant in the soil against a reference value.
3. What range of the Contamination Factor corresponds to the ‘considerable contamination’ level of degree of contamination?
a) CF less than 1
b) CF between 1 and 3
c) CF between 3 and 6
d) CF greater than 6
View Answer
Explanation: According to Hakanson, the considerable contamination degree is a range of values between 3 and 6. CF value less than 1 corresponds to low contamination; CF between 1 and 3 corresponds to moderate contamination; CF greater than 6 corresponds to very high contamination.
4. Nutrient excess in water bodies is caused by the process of eutrophication.
a) True
b) False
View Answer
Explanation: Nutrient excess causes eutrophication. This process, in turn, causes the uncontrollable growth of algae in water bodies. Excess accumulation of nutrients like nitrogen and phosphorus is responsible for this problem.
5. What is the cause of acidification of soil in ecosystems?
a) Accumulation of sulfur and nitrogen in the soil
b) Accumulation of sulfur and phosphorus in the soil
c) Accumulation of nitrogen and phosphorus in the soil
d) Accumulation of aluminium and phosphorus in the soil
View Answer
Explanation: The collection of sulfur and nitrogen in the soil results in its acidification. Although found naturally in the soil, these materials can accumulate in it. A phenomenon like acid rain is one such cause for such an accumulation.
6. Which of the following is an indicator of soil acidification?
a) Accumulation of sulfur in the soil
b) Accumulation of aluminium in the soil
c) Accumulation of nitrogen in the soil
d) Accumulation of phosphorus in the soil
View Answer
Explanation: A consequence of soil acidification is the accumulation of aluminium in the soil. Due to excess aluminium, aluminium toxicity occurs, which causes stunted root growth in plants.
7. How is the acidification of aquatic ecosystems detected?
a) By observation of dead zones in the water bodies
b) By detection of reduced dissolved oxygen in the water bodies
c) By detection of changes in pH in the water bodies
d) By observation of algae growth in the water bodies
View Answer
Explanation: An indicator of acidification in aquatic ecosystems is low pH. Accumulation of acids, heavy metals, salts, et cetera, in water bodies leads to this acidification.
8. Which of the following air pollutants is known to impact ecosystems directly?
a) Carbon dioxide
b) Water vapour
c) Sulphur dioxide
d) Ozone
View Answer
Explanation: Ozone directly impacts forests and alpine ecosystems by affecting plant productivity. It is known to affect photosynthesis in plants, as well as cause respiratory problems in humans. The other options have more indirect impacts.
9. Rivers are more likely to be polluted at a faster rate than lakes.
a) True
b) False
View Answer
Explanation: The opposite is true: lakes are more likely to get polluted faster than rivers. Rivers have the benefit of washing away toxic substances due to the motion of water and the water current.
10. Even a low concentration of pollutants like nitrogen can cause pollution in the ecosystems.
a) True
b) False
View Answer
Explanation: A slight increase in nutrient increases plant productivity. The opposite happens at a very high concentration of these nutrients, at which point they are categorised as pollutants.
11. Which of the following is a major cause of ocean acidification?
a) Condensation of water vapour into the oceans
b) Absorption of nitrogen dioxide by the oceans
c) Absorption of ozone by the oceans
d) Absorption of carbon dioxide by the oceans
View Answer
Explanation: Largely, ocean acidification occurs due to the absorption of carbon dioxide by ocean water. The bulk of the sea is too far to be affected by other gases. Also, the concentration of carbon dioxide is significantly high in the atmosphere, and it is distributed relatively uniformly here.
12. Below which pH level does an aquatic ecosystem lose most fish species?
a) Below pH 2
b) Below pH 3
c) Below pH 4
d) Below pH 5
View Answer
Explanation: Most fish species die out in pH levels below 4 and 4.5 since this level is too acidic for the fish to survive. Reproduction of fish is affected at pH level 5.
13. What happens when primary pollutants like volatile organic compounds and NOx interact in the atmosphere?
a) Volatile organic compounds suppress the effects of NOx
b) NOx and volatile organic compounds react to produce ozone
c) Volatile organic compounds enhance the effects of NOx
d) Volatile organic compounds make the detection of NOx difficult
View Answer
Explanation: Under the right conditions, secondary pollutants are products of the reaction between one or more primary pollutants. In this case, NOx and organic compounds are the primary pollutants, and ozone is the product. Ozone is a potent pollutant at ground level.
Sanfoundry Global Education & Learning Series – Pollution Control.
To practice all areas of Pollution Control, here is complete set of 1000+ Multiple Choice Questions and Answers.
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