Environment and Ecology has become indispensable for IAS Prelims Exam. Candidates cannot dispense with this section. In future also Importance of Environment and Ecology cannot be underestimated. Following are some MCQs that would help candidates to understand the kinds of questions they are going to face from Environment and Ecology section in IAS Prelims Exam:
Q1. Baval trees should be planted and used to prevent and control
a. Water pollution
b. Air pollution
c. Soil pollution
d. Noise pollution
Answer: b
Explanation: species of trees such as Baval (Acacia nilotica) which are least smoky should be planted and used to prevent and control air pollution.
Q2. Depletion of ozone layer causes, Which of the following?
1. Cataract in eyes leading to blindness
2. Reduced productivity of forests
3. Lung infection
Select the correct answer from the following codes
a. Only 1
b. Only 1 and 2
c. Only 2 and 3
d. 1,2 and 3
Answer: b
Explanation: Depletion of ozone layer permits passage of UV radiation on earth’s atmosphere which causes sunburn, cataract in eyes leading to blindness, skin cancer, reduced productivity of forests. Respiratory problems occur due to air pollution.
Q3. The protocol which decided to completely phase out CFC is
a. Cartagena protocol
b. Stockholm Convention
c. Montreal protocol
d. Kyoto protocol
Answer: c
Explanation: The Montreal protocol was amended in 1990 where it was decide to completely phase out CFC to prevent ozone layer depletion.
Q4. Which of the following is/are not Green House Gases?
1. Nitrous oxide
2. Ozone
3. Sulphur dioxide
Select the correct answer from the following codes
a. Only 3
b. Only 1 and 2
c. Only 2 and 3
d. 1,2 and 3
Answer: a
Explanation: Atmospheric gases like carbon dioxide, methane, nitrous oxide, water vapour, and Chlorofluorocarbons are capable of trapping the out-going infrared radiation from the earth.
Q5. With reference to effect of green house gases, Which of the following is/are true?
1. Changes to plant growth and nutrition levels
2. Ozone depletion
3. Smog pollution
Select the correct answer from the following codes
a.Only 1
b. Only 1 and 2
c. Only 2 and 3
d. 1,2 and 3
Answer: d
Explanation: ocean acidification, smog pollution, ozone depletion as well as changes to plant growth and nutrition levels.
Q6. With reference to sources of water pollution, which of the following is/are true?
1. Natural sources
2. Domestic sources
3. Agricultural sources
4. Industrial sources
Select the correct answer from the following codes
a. Only 4
b. Only 2, 3 and 4
c. Only 3 and 4
d. 1,2, 3 and 4
Answer: d
Explanation: Water pollution is caused by a variety of human activities such as industrial, agricultural and domestic and also by natural sources. Natural sources of pollution of water are soil erosion, leaching of minerals from rocks and decaying of organic matter.
Q7. Which of the following chemicals cause water pollution?
1. Arsenic
2. Copper
3. Zinc
Select the correct answer from the following codes
a. Only 1
b. Only 1 and 2
c. Only 2 and 3
d. 1,2 and 3
Answer: d
Explanation: Metals like lead, zinc, arsenic, copper, mercury and cadmium in industrial waste waters adversely affect humans and other animals. arsenic polluted water leads to accumulation of arsenic in the body parts like blood, nails and hairs causing skin lesions, rough skin, dry and thickening of skin and ultimately skin cancer.
Q8. Which of the following pairs are correctly matched?
Pollutant Disease
1. Arsenic Skin Cancer
2. Lead Itai – Itai
3. Cadmium displexia
Select the correct answer from the following codes
a. Only 1
b. Only 1 and 2
c. Only 2 and 3
d. 1,2 and 3
Answer: d
Explanation: Pollution of water bodies by mercury causes Minamata disease in humans and Dropsy in fishes. Lead causes displexia, cadmium poisoning causes Itai – Itai disease. Accumulation of arsenic in the body parts like blood, nails and hairs causing skin lesions, rough skin, dry and thickening of skin and ultimately skin cancer.
Q9. Consider the following statements
1. The Biological Demand for oxygen is directly proportional to the quantity of discharge of waste in water bodies.
2. Increase in water temperature decreases dissolved oxygen in water which adversely affects aquatic life.
Select the correct answer from the following codes
a. Only 1
b. Only 2
c. Both 1 and 2
d. Neither 1 nor 2
Answer: c
Explanation: Aquatic organisms are adopted to a uniform steady temperature of environment and any fluctuation in water temperature severely affects aquatic plants and animals. The biological demand for oxygen (BOD) increases with the increase in aquatic organisms.
Q10. With reference to Eutrophication, Which of the following is/are true?
1. It is phenomenon of nutrient enrichment of a water body
2. It depletes the water of dissolved oxygen (DO).
3. Human activities are mainly responsible for the eutrophication
Select the correct answer from the following codes
a. Only 1
b. Only 1 and 2
c. Only 2 and 3
d. 1,2 and 3
Answer: d
Explanation: Discharge of domestic waste, agricultural surface runoff, land drainage and industrial effluents in a water body leads to rapid nutrients enrichment in a water body. The excessive nutrient enrichment in a water body encourages the growth of algae, water hyacinth, Phytoplankton and other aquatic plants. The biological demand for oxygen (BOD) increases with the increase in aquatic organisms.
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