NEET Biology Environmental Issues MCQs Set 13

Answer: (c) Usnea (lichens)

Explanation:
1. Lichens are very sensitive to sulphur dioxide.
2. They disappear from polluted areas, so lichens such as Usnea are indicators of SO2 pollution.

Teacher's Note:
1. Lichens are used as bio-indicators of air pollution.
2. Their absence shows that the air is polluted.

Answer: (c) a non-degradable pollutant

Explanation:
1. DDT is not broken down by microbes and persists in the environment for a long time.
2. So it is a non-degradable pollutant.

Teacher's Note:
1. Non-degradable pollutants undergo biomagnification.
2. DDT causes thinning of eggshells in birds.

Answer: (d) they disrupt the ozone layer

Explanation:
1. CFCs release chlorine atoms in the stratosphere under UV radiation.
2. The chlorine atoms catalytically break down ozone, and NO2 and other nitrogen oxides also help to deplete ozone.

Teacher's Note:
1. One chlorine atom can destroy thousands of ozone molecules.
2. The Montreal Protocol controls the emission of such substances.

Answer: (d) it competes with O2 for haemoglobin

Explanation:
1. CO binds to haemoglobin about 200 times more strongly than oxygen does.
2. It forms carboxyhaemoglobin, which reduces the oxygen carrying capacity of blood.

Teacher's Note:
1. CO is a colourless, odourless gas from incomplete combustion.
2. It can cause death by asphyxia.

Answer: (a) SO2 and NO2

Explanation:
1. Sulphur dioxide and nitrogen dioxide dissolve in rain water to form sulphuric and nitric acids.
2. This lowers the pH of rain below 5.6.

Teacher's Note:
1. Acid rain damages monuments, buildings and crops.
2. The Taj Mahal is affected by it.

Answer: (c) substances that deplete the ozone layer

Explanation:
1. The Montreal Protocol (1987) is an international treaty to control the emission of ozone depleting substances.
2. It was signed in Montreal and came into force in 1989.

Teacher's Note:
1. The Kyoto Protocol deals with greenhouse gases.
2. The Montreal Protocol deals with ozone depleting substances.

Answer: (d) increase in the concentration of non-degradable pollutants as they pass through the food chain

Explanation:
1. Non-degradable pollutants such as DDT and mercury accumulate in the body.
2. Their concentration increases at each successive trophic level of the food chain.

Teacher's Note:
1. Top carnivores have the highest pollutant concentration.
2. Biomagnification causes eggshell thinning in birds.

Answer: (d) A-3, B-1, C-2

Explanation:
1. An electrostatic precipitator removes particulate matter (3).
2. A scrubber removes gases like SO2 (1) and a catalytic converter reduces automobile emissions (2).

Teacher's Note:
1. Catalytic converters change CO, hydrocarbons and NO into harmless gases.
2. They need unleaded petrol.

Answer: (a) 5th June

Explanation:
1. World Environment Day is celebrated every year on 5th June.
2. 16th September is World Ozone Day and 22nd April is Earth Day.

Teacher's Note:
1. Remember the dates of important environmental days.
2. 22nd March is World Water Day.

Answer: (c) Central Pollution Control Board

Explanation:
1. CPCB stands for Central Pollution Control Board.
2. It is the national body that monitors pollution in India.

Teacher's Note:
1. State level bodies are called State Pollution Control Boards.
2. The CPCB was set up under the Water Act.

Answer: (a) Kerala and Sri Lanka

Explanation:
1. Ecological sanitation (Ecosan) uses dry composting toilets.
2. They work in many areas of Kerala and Sri Lanka.

Teacher's Note:
1. Ecosan toilets turn human excreta into manure.
2. They save water and reduce pollution.

Answer: (d) A - 60% CO2, B - 20% CH4, C - 14% CFCs, D - 6% N2O

Explanation:
1. Carbon dioxide contributes about 60% of global warming, so it is the largest sector A.
2. Methane contributes about 20%, CFCs about 14% and nitrous oxide about 6%.

Teacher's Note:
1. Order the greenhouse gases by contribution: CO2, CH4, CFCs, N2O.
2. CO2 is the main gas because of its large quantity.

Answer: (d) none of these

Explanation:
1. Eutrophication is nutrient enrichment of water bodies and biomagnification is the build-up of pollutants in the food chain.
2. El Nino is a periodic warming of the Pacific Ocean.
3. The effect described is global warming, which is not among the options.

Teacher's Note:
1. Global warming is caused by an increase in greenhouse gases.
2. It leads to sea level rise and melting of ice.

Answer: (b) a(v), b(iii), c(iv), d(ii), e(i)

Explanation:
1. The Environment (Protection) Act was passed in 1986 and the Air Act in 1981.
2. The Water Act is of 1974, the Montreal Protocol of 1987 and the National Forest Policy of 1988.

Teacher's Note:
1. Water Act 1974, Air Act 1981, Environment Act 1986.
2. Remember them in this order.

Answer: (d) all of these

Explanation:
1. Ramesh Chandra Dagar, a farmer from Sonipat (Haryana), used integrated organic farming.
2. He combined bee-keeping, dairy management, water harvesting and composting.

Teacher's Note:
1. Integrated farming reduces the use of chemicals.
2. Dagar's work is a case study in the textbook.

Answer: (c) sulphur and aromatic hydrocarbons

Explanation:
1. Euro norms limit the sulphur and aromatic hydrocarbon content of fuel.
2. Euro-II allows less sulphur and aromatics than the earlier norms.

Teacher's Note:
1. Bharat stage norms in India follow the Euro norms.
2. They aim to cut vehicular pollution.

Answer: (a) Garhwal Himalayas

Explanation:
1. In the Chipko movement of 1974, villagers hugged trees to stop them from being cut.
2. It started in the Garhwal Himalayas in Uttarakhand.

Teacher's Note:
1. The Appiko movement is its counterpart in South India.
2. The Bishnoi movement was in Rajasthan.