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Class 12 Biology MCQ Questions of Environmental Issues with Answers?

Answer 1

The important Class 12 Biology MCQ Questions of Environmental Issues with Answers pattern with the help of using Sarthaks eConnect is one of the maximum dependable MCQ Questions because it covers all of the important chapters that are withinside the syllabus.

MCQ Questions for Class 12 Biology with Answers are organized according to the recent syllabus and examination pattern. Students can solve those Environmental Issues Class 12 MCQ Questions with Answers and check their practice level. Students are suggested to solve the Class 12 Biology MCQ Questions of Environmental Issues with Answers is available here.

The college students who are focused on Board and NEET exams must prepare for all of the crucial chapters of the Syllabus to secure maximum marks in Board and NEET Exams. 

Practice MCQ Question for Class 12 Biology chapter-wise

1. Which chemical substance affects the Ozone Layer?

(a) Chlorofluorocarbon
(b) Chlorine
(c) Hexafluorocarbon
(d) Molecular Carbon

2. In Ozone Degradation which element acts as catalyst?

(a) Chlorine
(b) Flurine
(c) Oxygen
(d) Potassium

3. Ozone Layer is found in :

(a) Stratosphere
(b) Lithosphere
(c) Troposphere
(d) Hemisphere

4. Fluoride pollution mainly affect:

(a) Teeth
(b) Kidney
(c) Brain
(d) Heart

5. Nutrient enrichment of water bodies causes:

(a) Stratification
(b) Eutrophication
(c) Succession
(d) None of these

6. Increased skin cancer and high mutation rate are due to:

(a) Acid Rain
(b) Ozone Depletion
(c) CO₂ Pollution
(d) CO Pollution

7. Minimata disease is caused by:

(a) ByChromium
(b) By Cadmium
(c) By Methyl mercury
(d) By Radioactive elements

8. Bluebaby syndrome results from:

(a) Excess of TDS
(b) Excess of DO
(c) Excess of chloride
(d) Methaemoglobin

9. Pollutant which causes acid rain is:

(a) SO₂
(b) CO₂
(c) CO
(d) Hydrocarbon

10. Common indicator organism of water pollution is:

(a) Lemna pancicostata
(b) Eichhomia crassipes
(c) Escherichia coli
(d) Entamoeba histolytica

11. Large-scale disposal of solid waste in low areas of the ground and then covering it with earth is called

(a) Deep well injection
(b) Landfill
(c) Pyrolysis
(d) Incineration

12. A river with an inflow of domestic sewage rich in organic waste may result in

(a) drying of the river very soon due to algal bloom
(b) increased population of aquatic food web organisms
(c) an increased production of fish due to biodegradable nutrients
(d) death of fish due to lack of oxygen

13. Joint Forest Management Concept was introduced in India during

(a) 1960s
(b) 1970s
(c) 1980s
(d) 1990s

14. What is the 3R approach?

(a) Reduce, Remove and Replenish
(b) Reduce, Remove and Reuse
(c) Reuse, Replenish and Remove
(d) Reduce, Reuse and Recycle

15. The term biomagnification refers to the

(a) Growth of organisms due to food consumption
(b) Blowing up of environmental issues by man
(c) Increase in the concentration of non-degradable pollutants as they pass through the food chain
(d) Increase in population size

16. Substances which can be broken down into non-poisonous substances by the action of microorganisms are said to be

(a) Non-degradable
(b) Non-biodegradable
(c) Non-decomposable
(d) Biodegradable

17. Eutrophication of water bodies leading to killing of fishes is mainly due to non-availability of :

(a) Light
(b) Essential minerals
(c) Oxygen
(d) Food

18. The UN conference of Parties on climate change in the year 2012 was held at:

(a) Doha
(b) Lima
(c) Warsaw
(d) Durban

19. The highest DDT concentration in aquatic food chain shall occur in 

(a) phytoplankton
(b) seagull
(c) crab
(d) eel

20. The zone of atmosphere in which the ozone layer is present is called

(a) ionosphere
(b) mesosphere
(c) stratosphere
(d) troposphere

21. A scrubber in the exhaust of a chemical industrial plant removes

(a) Gases like sulphur dioxide
(b) Particulate matter of the size 5 micrometer or above
(c) Gases like ozone and methane
(d) Particulate matter of the size 2.5 micrometer or less

22. Kyoto Protocol was endorsed (supported) at

(a) CoP-3
(b) CoP-5
(c) CoP-6
(d) CoP-4

23. Eutrophication is often seen in

(a) fresh water lakes
(b) ocean
(c) mountains
(d) deserts

24. Which one of the following is being tried in India as a biofuel substitute for fossil fuels?

(a) Jatropha
(b) Azadirachta
(c) Musa
(d) Aegilops

25. Green muffler is used against which type of pollution?

(a) Air
(b) Water
(c) Soil
(d) Noise

Answer 2

1. Answer : (a) Chlorofluorocarbon   

Explanation: Ozone depleting substances are chemicals that destroy the earth's protective ozone layer. They include: chlorofluorocarbons (CFCs) halon.

2. Answer : (a) Chlorine

Explanation: In stratosphere , Cl acts as a catalyst in the degradation of ozone and release of molecular oxygen . It is released by action of UV rays on a chlorofluorocarbon .

3. Answer : (a) Stratosphere

Explanation: The ozone layer is the common term for the high concentration of ozone that is found in the stratosphere around 15–30km above the earth's surface. It covers the entire planet and protects life on earth by absorbing harmful ultraviolet-B (UV-B) radiation from the sun.

4. Answer : (a) Teeth

Explanation: Fluorine pollution mainly affects teeth.Water fluoridation has occurred in many developing countries as an act to improve dental health. Nowadays many toothpaste companies are also including fluoride in their product.

5. Answer : (b) Eutrophication

Explanation: Eutrophication, is nutrient enrichment; it drives excess primary productivity in waterways. It can be either natural or caused by human impact. For example, high concentrations of nutrients may encourage algal growth and result in nuisance or toxic algal blooms.

6. Answer : (b) Ozone Depletion

Explanation: Increasing skin cancer and a high mutation rate are the results of Ozone depletion. An increased amount of manufactured chemicals such as manufactured halocarbon refrigerants, solvents, propellants, and foam-blowing agents are the major causes of ozone depletion in the stratosphere.

7. Answer : (c) By Methyl mercury

Explanation: Minamata disease is a methylmercury poisoning with neurological symptoms and caused by the daily consump- tion of large quantities of fish and shellfish that were heavily contaminated with the toxic chemical generated in chemical factories and then discharged into the sea.

8. Answer : (d) Methaemoglobin

Explanation: The most common cause of blue baby syndrome is water contaminated with nitrates. After a baby drinks formula made with nitrate-rich water, the body converts the nitrates into nitrites. These nitrites bind to the hemoglobin in the body, forming methemoglobin, which is unable to carry oxygen.

9. Answer : (a) SO₂

Explanation: Acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air.In addition, the exhaust from cars, trucks, and buses releases nitrogen oxides and sulfur dioxide into the air. These pollutants cause acid rain.

10. Answer : (c) Escherichia coli

Explanation: A common indicator organism of water pollution is Escherichia coli. Escherichia coli is transmitted to water bodies through fecal matter.

11. Answer : (b) Landfill

Explanation: Landfill is the oldest and most common form of waste disposal, although the systematic burial of the waste with daily, intermediate and final covers only began in the 1940s. In the past, refuse was simply left in piles or thrown into pits; in archeology this is known as a midden.

12. Answer : (d) death of fish due to lack of oxygen

Explanation: A river consisting of domestic sewage rich in organic waste will decrease the DO (dissolved oxygen). The organic waste will raise biological oxygen demand of the river thus depleting the O₂ content and may result in death of fish due to lack of oxygen.

13. Answer : (c) 1980s

Explanation: Joint Forest Management Concept was introduced in India during 1980s.

14. Answer : (d) Reduce, Reuse and Recycle

Explanation: The 3R (Reduce-Reuse-Recycle) Concept is a sequence of steps on how to manage waste properly. The top priority is Reduce, which is to reduce waste generation, then Reuse, and then Recycle, to give waste material a second chance before disposing them to the landfill.

15. Answer : (c) Increase in the concentration of non-degradable pollutants as they pass through the food chain

Explanation: Biomagnification is defined as the accumulation of a particular substance in the body of the organisms at different trophic levels of a food chain. One example of biomagnification is the accumulation of insecticide DDT which gets accumulated in zooplanktons. Small fishes consume these zooplanktons.

16. Answer : (d) Biodegradable

Explanation: Those waste materials which can be broken down to non-poisonous substances in nature in due course of time by the action of micro-organisms are called biodegradable wastes

17. Answer : (c) Oxygen

Explanation: Eutrophication is the excessive growth of algae, plants and animals in water bodies due to the nutrient enrichment, particularly with nitrogen and phosphate. There is a drastic decrease in oxygen replenishment inside water. Non-availability of oxygen results in the death of aquatic animals.

18. Answer : (a) Doha

Explanation: The conference took place from Monday 26 November to Saturday 8 December 2012, at the Qatar National Convention Centre in Doha.

19. Answer : (b) seagull

Explanation: Seagulls feed on the dead or alive fishes and will contain the highest DDT concentration.

20. Answer : (c) stratosphere

Explanation: The ozone layer is formed in the stratosphere layer of the atmosphere. This layer is present at approximately 15-30km away above the surface of the Earth.

21. Answer : (a) Gases like sulphur dioxide

Explanation: A scrubber can remove gases like sulphur dioxide. In a scrubber, the exhaust is passed through a spray of water or lime water.Lime reacts with sulphur dioxide to produce a precipitate of calcium sulphate or sulphite, used to remove soluble gases and particles.

22. Answer : (a) CoP-3

Explanation: The Kyoto Protocol was agreed upon the third session of the Conference of Parties to the UNFCCC (COP 3) in 1997 in Kyoto, Japan. The Kyoto Protocol is an international treaty, which adds on to the United Nations Framework Convention on Climate Change (UNFCCC), 1992.

23. Answer : (a) fresh water lakes

Explanation: Eutrophication is often seen in fresh-water lakes. Eutrophication is the process of nutrient enrichment of water and consequent loss of species diversity.

24. Answer : (a) Jatropha

Explanation: Petro plans are the plants which can yield a large amount of latex having long chained liquid hydrocarbon, eg, Jatropha, Euphorbia (family-Euphorbiaceae) and other members of Euphorbiaceae, Asclepiadaceae, Apocyanaceae. The wood used as a source of energy is called fuel wood.

25. Answer : (d) Noise

Explanation: Green Muffler is a technique which is used for reducing the noise pollution by planting 4-6 rows around the most populated areas or the noisy places like along the roadsides, industrial areas, societies which are located near the highways, etc.

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