NEET Biology Environmental Issues MCQs Set 17

Answer: (b) Noise pollution

Explanation:
1. Acoustic zoning is related with noise pollution.
2. Hence option (b) is correct: Noise pollution

Teacher's Note:
1. Acoustic zoning means dividing areas by permissible noise level.
2. It is a method of noise control.

Answer: (b) O₃

Explanation:
1. A chemical weed in trophosphere and protection in stratosphere is ozone.
2. Hence option (b) is correct: O₃

Teacher's Note:
1. Ozone is harmful in the troposphere but protective in the stratosphere.
2. This is why it is called good up there and bad down here.

Answer: (d) Finally decreased COD

Explanation:
1. Eutrophication finally increased COD (Chemical Oxygen Demand).
2. Hence option (d) is correct: Finally decreased COD

Teacher's Note:
1. During eutrophication algal bloom, oxygen depletion and fish death occur, and BOD finally increases.
2. So COD does not decrease.

Answer: (d) Faecal pollution

Explanation:
1. Presence of Escherichia coli in waste indicates faecal pollution.
2. Hence option (d) is correct: Faecal pollution

Teacher's Note:
1. E. coli lives in the human intestine, so its presence in water shows faecal contamination.
2. It is the standard indicator organism.

Answer: (b) High concentrations of DDT disturb calcium metabolism in birds.

Explanation:
1. High concentration of DDT disturb calcium metabolism in birds due to biomagnification.
2. Hence option (b) is correct: High concentrations of DDT disturb calcium metabolism in birds.

Teacher's Note:
1. DDT in high concentration thins eggshells in birds by disturbing calcium metabolism.
2. This lowers the hatching success of eggs.

Answer: (c) Agricultural runoff

Explanation:
1. Non-point source of water pollution is agricultural runoff.
2. Hence option (c) is correct: Agricultural runoff

Teacher's Note:
1. Non-point sources have no single discharge pipe, e.g. agricultural runoff.
2. Sewage outlets and factory effluents are point sources.

Answer: (b) Poor aeration and high salinity

Explanation:
1. Prolonged water logging in an agricultural fields is likely to create the problem of poor aeration and high salinity.
2. Hence option (b) is correct: Poor aeration and high salinity

Teacher's Note:
1. Waterlogging reduces soil aeration and brings salts to the surface, causing salinity.
2. Prolonged irrigation has a similar effect.

Answer: (d) Decrease in BOD of pond water – Increase in global temperature

Explanation:
1. Decreased in BOD of pond water, decreases water pollution.
2. Hence option (d) is correct: Decrease in BOD of pond water – Increase in global temperature

Teacher's Note:
1. Coal burning releases SO2, CFCs deplete ozone, and nutrient enrichment causes eutrophication.
2. The odd one links a decrease of BOD with warming, which has no basis.

Answer: (d) Production of adverse ecological effect by a previously useful chemical

Explanation:
1. Ecological backlash / Ecological boomerang is production of adverse ecological effect by a previously useful chemical.
2. Hence option (d) is correct: Production of adverse ecological effect by a previously useful chemical

Teacher's Note:
1. Ecological backlash means a once useful chemical ends up causing harmful ecological effects, e.g. DDT.
2. It is also called ecological boomerang.

Answer: (a) Absorbers of long-wave radiations from earth

Explanation:
1. Green house gases absorb of long-wave radiations (infrared) from earth.
2. Hence option (a) is correct: Absorbers of long-wave radiations from earth

Teacher's Note:
1. Greenhouse gases transmit incoming solar radiation but absorb outgoing long-wave infrared.
2. This traps heat in the lower atmosphere.

Answer: (a) Kyoto Protocol, 1997

Explanation:
1. Hence option (a) is correct: Kyoto Protocol, 1997

Teacher's Note:
1. The Kyoto Protocol (1997) fixed binding emission cuts for developed countries, about 5% below 1990 levels.
2. The Montreal Protocol deals with ozone depleting substances.

Answer: (b) Cl

Explanation:
1. UV rays act on CFCs, releasing Cl atoms, chlorine reacts with ozone in sequential method converting into oxygen. Carbon, oxygen and Fe are not related to ozone layer depletion.
2. Hence option (b) is correct: Cl

Teacher's Note:
1. Chlorine atoms from CFCs act as catalysts and convert ozone into oxygen without being consumed.
2. One Cl atom can destroy many thousand ozone molecules.

Answer: (d) 16th September

Explanation:
1. World Ozone day is celebrated on 16th September. 5th June - World Environment Day 21st April - National Yellow Bat Day 22nd April - National Earth Day
2. Hence option (d) is correct: 16th September

Teacher's Note:
1. World Ozone Day is observed on 16 September, commemorating the 1987 Montreal Protocol.
2. Do not confuse it with Environment Day on 5 June.

Answer: (c) Petroleum industry

Explanation:
1. Biochemical oxygen demand (BOD) is not a good index for pollution for water bodies receiving effluents from petroleum industry as the generated waste is mostly non-biodegradable in nature.
2. Hence option (c) is correct: Petroleum industry

Teacher's Note:
1. BOD measures biodegradable organic matter only.
2. Petroleum effluents contain non-biodegradable hydrocarbons, so BOD is a poor index there.

Answer: (b) Seagull

Explanation:
1. Maximum DDT concentration occurs in fish eating birds like seagull due to biomagnification. This happens because a toxic substance accumulated by an organism cannot be metabolised or excreted, thus passed to higher trophic level.
2. Hence option (b) is correct: Seagull

Teacher's Note:
1. DDT biomagnifies, so the top consumer, a fish eating bird like the seagull, has the highest concentration.
2. Note that biomagnification increases at each trophic level.

Answer: (a) Oxygen

Explanation:
1. During eutrophication of water bodies, BOD level increases due to rapid growth of microbes.
2. Hence option (a) is correct: Oxygen

Teacher's Note:
1. Eutrophication kills fish by oxygen depletion when decomposers consume dissolved oxygen.
2. Minerals are in excess, not lacking.

Answer: (b) Biomagnification

Explanation:
1. Increase in concentration of toxic substances in successive trophic level.
2. Hence option (b) is correct: Biomagnification

Teacher's Note:
1. Biomagnification is the increase of a toxicant concentration at successive trophic levels.
2. It occurs for non-degradable, fat soluble substances.

Answer: (b) Pesticide pollution

Explanation:
1. Pesticides, i.e., DDT (Biomagnification) related book.
2. Hence option (b) is correct: Pesticide pollution

Teacher's Note:
1. Rachel Carson's Silent Spring warned about pesticides such as DDT.
2. It started the modern environmental movement.

Answer: (d) Radioactive fall out engulfed Bhopal

Explanation:
1. It was not radioactive radiation release.
2. Hence option (d) is correct: Radioactive fall out engulfed Bhopal

Teacher's Note:
1. The Bhopal tragedy (December 1984) was caused by methyl isocyanate leakage.
2. There was no radioactive fall-out.

Answer: (d) SPM

Explanation:
1. Suspended Particulate Matter.
2. Hence option (d) is correct: SPM

Teacher's Note:
1. An electrostatic precipitator charges suspended particles and collects them on plates.
2. It controls suspended particulate matter (SPM), not gases.