Additional Questions - Chapter 12 Environmental Issues 12th Biology Zoology Guide Samacheer Kalvi Solutions - SaraNextGen [2024-2025]

Updated By SaraNextGen

On April 24, 2024, 11:35 AM

Additional Questions and Answers

1 – Mark Questions

Question 1.
The gaseous envelope which surrounds the Earth is called as ________
(a) Stratosphere
(b) Atmosphere
(c) Troposphere
(d) Ozonosphere
Answer:
(b) Atmosphere

Question 2.
are the major causes of CO polution in large cities and towns ________
(a) Fossil fuels
(b) Ocean
(c) Deforestation
(d) Automobiles
Answer:
(d) Automobiles

Question 3.
and are the major cause for acid rain ________
(a) Sulphur di oxide and Hydrogen peroxide
(b) Hydrogen peroxide and Sulphuric acid
(c) Hydrochloride and sulphur dioxide
(d) Sulphur dioxide and Nitrogen oxide
Answer:
(d) Sulphur dioxide and Nitrogen oxide.

Question 4.
What is the name of the app published by Central Pollution Control Board that provides updates on AQI
(a) Hamear
(b) Jhoan
(c) Sameer
(d) Industan
Answer:
(c) Sameer

Question 5.
PAN stands for ________
(a) Peroxy acetic nitrogen
(b) Perchloro acetate
(c) Peroxyacetyl nitrate
(d) Peractyl nitroxide
Answer:
(d) Peroxyacetyl nitrate

Question 6.
Average human consumption of oxygen per day is ________
(a) 280 L
(b) 550 L
(c) 620 L
(d) 730 L
Answer:
(b) 550 L

Question 7.
Name the famous flagship programme of Central Government launched to achieve pollution abatement and rejuvenation of River Ganga.
Answer:
Namami Gange

Question 8.
The intensity of noise is measured in ________
(a) Dobson
(b) Hertz
(c) Decibel
(d) Frequency
Answer:
(c) Decibel

Question 9.
According to noise pollution rules 2000, the permissible level of noise in commercial area is during day and during night
(a) 55 db, 65 db
(b) 65 db, 55 db
(c) 70 db, 60 db
(d) 75 db, 65 db
Answer:
(b) 65 db, 55 db

Question 10.
Which is not a physical method of waste water treatment ________
(i) Floatation
(ii) Filtration
(iii) Phydro remediation
(iv) Oxidation
(a) i and iii
(b) ii and iv
(c) i and ii
(d) iii and iv
Answer:
(d) iii and iv

Question 11.
Match List I with List II

Answer:
a – iv, b – i,b c – ii, d – iii

Question 12.
Which is not a method of disposal of radioactive waste.
(a) Dilute and dispense
(b) Delay and decay
(c) Recycle and reuse
(d) Limit generation
Answer:
(c) Recycle and reuse

Question 13.
E-Wastes are basically ________
(a) Poly iodinated biphenyl based compounds
(b) Poly chlorinated biphenyl based compounds
(c) Poly hydroxy biphenyl based compounds
(d) Poly acetyl biphenyl based compounds
Answer:
(c) Poly hydroxy biphenyl based compounds

Question 14.
Identify the correct statement indicating 4Rs of treating water.
(a) Regenerate, Reduce, Reuse and Recycle
(b) Refuse, Reduce, Rejenuvate and Reuse
(c) Redeem, Refuse, Rejenuvate and Reduce
(d) Refuse, Reduce, Rescue and Recycle.
Answer:
(d) Refuse, Reduce, Rescue and Recycle.

Question 15.
UN conference on Sustainable development in 2012 was held at ________
(a) Ruanda
(b) Rio de Janeiro
(c) Geneva
(d) Stockholm
Answer:
(b) Rio de Janeiro

Question 16.
The molecular formula for ozone is ________
(a) O₂
(b) O₄
(c) O₃
(d) O₇
Answer:
(c) O₃

Question 17.
World Ozone Day was observed on ________
(a) September 16th
(b) October 12th
(c) December 1st
(d) August 18th
Answer:

Question 18.
Who is the leader of Chipko Movemet?
Answer:
Sunderlal Bahuguna

Question 19.
I am called as the Forest Man of India? Who am I?
Answer:
JadavPayeng

Question 21.
Identify the incorrect statement.
(i) EcoSan toilets is a sustainable way for handling human excreta by using dry composting toilets
(ii) It reduces waste water generation
(iii) It is based on recovery and recycling of nutrients from excreta
(iv) EcoSan toilets are used in several parts of India and Srilanka.
(a) i and ii only
(b) iii and iv only
(c) all the above
(d) none of the above
Answer:
(d) none of the above

Question 22.
What is the name of the action plan for sustainable development framed in Rio conference in in 1992?
(a) Action 21
(b) Declaration 21
(c) Protocol 21
(d) Agenda 21
Answer:
(d) Agenda 21

Question 23.
Eutrophication is a result of ________
(a) Agricultural and sewage waste
(b) Vehical emission
(c) Pesticides
(d) Indutrial effluent
Answer:
(c) Pesticides

Question 24.
BOD stands for ________
(a) Biological Oxidation Demand
(b) Biotic Oxygen Deficient
(c) Biological Oxygen Deficit
(d) Biochemical
Answer:
(a) Biologoical Oxidation Demand

Question 25.
Stratosphere is mainly depleted by ________
(a) Excess CO
(b) CFC’s
(c) Ozone
(d) Exess CO
Answer:
(b) CFC’s

Question 26.
Treatment of sewage involves
(a) Floatation, Filtration and Sedimentation of suspended particles
(b) Aerating it for bacterial action
(c) Removal of nitrates and phosphates
(d) All of the above
Answer:
(d) All of the above

Question 27.
Assertion (A): Ozone layer protects the UV rays entering the Earth.
Reason (R): UV rays may cause melanoma
(a) A is right R is wrong
(b) A is wrong R is right
(c) Both A and R are correct
(d) R explains A
Answer:
(d) R explains A

Question 28.
Assertion (A): Evolution of Greenhouse gases leads to Global warming
Reason (R): The energy released by the greenhouse gases move away from the atmospheric surface
(a) A is right R is wrong
(b) A is wrong R is right
(c) Both A and R are correct
(d) R explains A
Answer:
(a) A is right R is wrong

Question 29.
Statement (1): Incomplete combination of fossil fuels release CO
Statement (2): CO is a GHG
(a) Statement 1 is true, statement 2 is false
(b) Statement 1 is false, statement 2 is true
(c) Both Statements 1 and 2 are true
(d) Both statements 1 and 2 are false
Answer:
(c) Both statements 1 and 2 are true.

Question 30.
Statement (1): The intensity of noise is measured in dobson (dB) unit.
Statement (2): Noise provides immense bliss.
(a) Statement 1 is true, statement 2 is false
(b) Statement 1 is false, statement 2 is true
(c) Both Statements 1 and 2 are true
(d) Both statements 1 and 2 are false
Answer:
(d) Both statements 1 and 2 are false.

Question 31.
The threshold of noise level is ________
Answer:
120db

Question 32.
Chemicals used in agriculture as fertilizer and pesticides are generally called as ________
Answer:
Agrochemicals

2 – Mark Questions

Question 1.
Define pollution.
Answer:
Pollution is any undesirable change in the physical, chemical and biological characteristics of the environment due to natural causes and human activities.

Question 2.
What is air pollution?
Answer:
The alterations or changes in the composition of the Earth’s atmosphere by natural or human activities (anthropogenic factors) are referred as Air Pollution.

Question 3.
Classify air pollutants.
Answer:
Air pollutants can be

· discharge of dusts or particulate matter (PM: 2.5 and 10)

· discharge of gases (SO_x, NO_x, CO and CO₂)

Question 4.
What are particulate matters? Give examples.
Answer:
Particulate matters are tiny particles of solid matter suspended in a gas or liquid. Combustion of fossil fuels, fly ash produced in thermal power plants, forest fires, asbestos mining units and cement factories are the main sources of particulate matter pollution.

Question 5.
Name the secondary pollutant in photochemical smog. Mention its adverse effect.
Answer:
Peroxyacetyl nitrate (PAN) is a secondary pollutant present in photochemical smog. It is thermally unstable and decomposes into peroxyethanol radicals and nitrogen dioxide gas causing eye irritation.

Question 6.
How ozone hole is developed?
Answer:
Ozone depletion: Thinning of the stratospheric ozone layer is known as ozone depletion. Such depletion causes the ‘ozone hole’, resulting in poor screening of the harmful UV rays and increase in incidences of skin cancer. Some of the common agents that deplete ozone are CFCs.

Question 7.
List out the green house gases.
Answer:
(a) CO₂
(b) CFCs
(c) Methane
(d) Nitrous oxide

Question 8.
What is Acid rain?
Answer:
Acid rain is a form of precipitation that contains acidic components, such as sulfuric acid or nitric acid. It damages trees, crops and harms marine animals (coral reefs) and induces corrosion.

Question 9.
Point out any two non-point sources of water pollution.
Answer:

1. Agriculture chemical run off.

2. Dumping of plastics in water bodies.

Question 10.
How will you define noise pollution?
Answer:
Sound that is unwanted and undesirable or can disrupt one’s quality of life is called as Noise. When there is lot of ‘noise’ in the environment, it is termed as Noise Pollution.

Question 11.
Expand USEPA and MOEFCC.
Answer:

1. USEPA : United States Environmental Protection Agency.

2. MOEFCC : Ministry of Environment, Forest and Climate Change.

Question 12.
What are agrochemicals?
Answer:
Chemicals which are used in agriculture for growth of plants and pest control are called agrochemicals or agrichemicals.

Question 13.
Which organism is affected by colony collapse syndrome? What will be the impact?
Answer:
Colony collapse syndrome in Honey bees due to pesticides/herbicides can lead to destruction of hives and lower agricultural productivity.

Question 14.
Define the term eutrophication.
Answer:
When run-off from land containing nutrients reaches water bodies like lakes, it results in dense growth of plant life. This phenomenon is called Eutrophication.

Question 15.
What is meant by accelerated eutrophication?
Answer:
Pollutants from anthropogenic activities like effluents from the industries and homes can radically accelerate the aging process. This phenomenon is known as Cultural or Accelerated Eutrophication.

Question 16.
List out the chemical methods of wastewater treatment.
Answer:
Chemical methods of wastewater treatment include:

1. Generation of insoluble solids.

2. Produce an insoluble gas.

3. Produce biologically degradable substances from a non-biodegradable substance.

4. Oxidize or reduce to produce a non-objectionable substance.

Question 17.
Expand RZWT and DEWATS.
Answer:

1. RZWT : Root Zone Wastewater Treatment

2. DEWATS : Decentralized Wastewater Treatment System

Question 18.
What are medical wastes?
Answer:
Any kind of waste that contains infectious material generated by hospitals, laboratories, medical research centers, Pharmaceutical companies and Veterinary clinics are called medical wastes.

Question 19.
What does 4R stands for?
Answer:
‘4R’ refers to Refuse, Reduce, Reuse and Recycle methods to manage plastic waste.

Question 20.
Define deforestation.
Answer:
Deforestation is the destruction of forests in order to clear the land and make it available for other uses.

3 – Mark Questions

Question 21.
Classify degradable pollutants.
Answer:
Based on the time taken to breakdown into their ingredients, degradable pollutants are classified as rapidly degradable (non-persistent) and slowly degradable (persistent).

1. Rapidly degradable or non-persistent pollutants: These can be broken down by natural processes. Domestic sewage and vegetable waste are examples of such pollutants.

2. “Slowly degradable or persistent pollutants: These are pollutants that remain in the environment for many years in an unchanged condition and take decades or longer to degrade, as in the case of DDT.

Question 22.
What are the main sources of air pollution?
The main sources of air pollution are:

1. Transport sources – cars, buses, airplanes, trucks and trains.

2. Stationary sources – power plants, incinerators, oil refineries, industrial facilities, and factories.

3. Area sources – agricultural – wood / stubble burning and fireplaces.

4. Natural sources – wind-blown dust, wildfires and volcanoes.

Question 23.
Define AQI. What will be the air quality if AQI is between 0-50?
Answer:
Air Quality Index (AQI) is a number used by government agencies to communicate to the public how polluted the air is at a given time. If AQI is between 0-50 then the quality of air is good.

Question 24.
Explain the three main sources of water pollution.
Answer:

1. There are three main types of sources: point sources, non-point sources, leaks and spills.

2. Point sources: Discharge of pollutants at specific locations through pipelines or sewers into the water body. Factory effluents, sewage, underground mines, oil wells, oil tankers and agriculture are common point sources.

3. Non-point sources: Sources that cannot be traced to a single site of discharge like acid rain, dumping of the plastics in water bodies and agriculture chemical run off are common examples.

4. Leaks and Spills: This occurs mostly due to ship collision, off shore oil rigs, oil leakages and discharges into sea.

Question 25.
What will be the impact of water pollution on ecosystem?
Answer:
Destruction of ecosystems: Ecosystems, especially aquatic systems, can be severely affected or destroyed by water pollution.Water pollutants affect existing niches and habitats and the survival of organisms. Soil fertility is affected and the system becomes uninhabitable.

Question 26.
Suggest few ways to control water pollution.
Answer:

1. Regulate or control of pollutant(s) discharge at the point of generation.

2. Wastewater can be pretreated by scientific methods before discharge to municipal treatment sources.

3. Setting up of Sewage Treatment Plants (STP) and Effluent Treatment Plants (ETP).

4. Regulate or restrict the use of synthetic fertilisers and pesticides.

5. Public awareness and peoples’ involvement is essential.

Question 27.
Write a note on ‘Namami Ganga’ programme.
Answer:
Namami Gange (National Mission for Clean Ganga) Programme is an Integrated Conservation Mission approved as the ‘Flagship Programme’ of the Union Government in June 2014 with a budget outlay of 20,000 crores to accomplish the twin objectives of effective abatement of pollution, conservation and rejuvenation of River Ganga.

Question 28.
List out the sources of noise pollution.
Answer:
‘Vehicle engines, air horns, audio video systems, trains, low flying aircrafts, factory machines, sirens, motors, drillers and crushers, compressor machines, crackers, explosives and modem supersonic transports are the common sources of noise pollution.

Question 29.
State the role of Government in controlled Noise pollution.
Answer:
Article 48-A and Article 51-A of the Constitution of India, Noise Pollution (Regulation and Control) Rules 2000, and Tamil Nadu State Environment Policy 2017 are some of the legal relief from noise pollution. According to Noise Pollution (Regulation and Control) Rules, 2000, the permissible limit of noise in areas categorized as commercial is 65 decibels (dB) during day and 55 dB during night.

Question 30.
Comment on Bio-magnification of DDT.
Answer:
When non-degradable substances enter the food chain, they do not get metabolized or broken down or expelled and instead get transferred up the tropic levels of the food chain. During this process, they show an increase in concentration which is referred to as biomagnification. This results in increased toxicity and may even be lethal. This phenomenon is well established for mercury and DDT.

Question 31.
Explain biological methods of waste water treatment.
Answer:
Biological methods of Wastewater treatment:

1. Bioremediation of wastewater includes the aerobic treatment (oxidation ponds and aeration lagoons) and anaerobic treatment (anaerobic bioreactors and anaerobic lagoons).

2. Phytoremediation of wastewater includes constructed wetlands, Root Zone Wastewater Treatment (RZWT), and Decentralized Waste Water Treatment System (DEWATS).

Question 32.
Write a note on organic farming.
Answer:
Organic farming is a method of farming system which primarily aims at cultivating the land and raising crops in such a way, so as to keep the soil alive and in good health by use of organic wastes (crop, animal and farm wastes, aquatic wastes) and other biological materials along with beneficial microbes (biofertilizers) to release nutrients to crops for increased sustainable production in an eco-friendly pollution free environment.

Question 33.
How radioactive wastes are generated?
Answer:
Radioactive wastes are generated during various operations of the nuclear power plant. Radioactive waste can be in gas, liquid or solid form, and its level of radioactivity can vary. The waste can remain radioactive for a few hours or several months or even hundreds of thousands of years. Depending on the level and nature of radioactivity, radioactive wastes can be classified as Exempt Waste, Low and Intermediate Level Waste and High Level Waste.

Question 34.
What are geological repositories?
Answer:
Geological Repositories – A deep geological repository is a nuclear waste repository excavated deep within a stable geologic environment. It is suited to provide a high level of long-term isolation and containment without future maintenance. In India at Tarapur and Kalpakkam, a wet storage facility of Spent Fuel is the main mode of storage.

Question 35.
Give an account on E-waste.
Answer:
Electronic waste or e-waste describes discarded electrical electronic devices as well as any refuse created by discarded electronic devices and components and substances involved in their manufacture or use. Their disposal is a growing problem because electronic equipment frequently contains hazardous substances.

In a personal computer, for example, there may be lead (Pb) in the cathode ray tube (CRT) and soldering compound, mercury (Hg) in switches and housing, and cobalt (Co) in steel components, among other equally toxic substances. E-wastes are basically PCB (Polychlorinated bipheny) based, which are non-degradable.

Question 36.
What will be the impact of global warming?
Answer:
The large-scale global warming will have significant impact on people and nature. As global average temperatures rise, precipitation patterns could be, affected. Extreme wet and dry conditions can be expected (flooding and desertification). Coastal areas shall become more vulnerable to storm surges as sea level rises. Plant and animal species will migrate or disappear in response to climate change.Global warming can directly affect the flora and fauna. This could also result in shortage of food and even lead to food crisis; and affect the health of the people and organisms.

Question 37.
Explain the process of Ozone formation in atmosphere.
Answer:
Ozone is found in the layer of the atmosphere called the Stratosphere. It acts as a protective covering that absorbs ultraviolet (UV) radiation from the Sun. The ozone molecule (O₃) consists of three oxygen atoms. It is formed when atmospheric oxygen (O₂) on exposure to solar radiation breaks into two oxygen atoms; each atom then joins up with a single oxygen atom. The ozone molecule is unstable. It soon decays again to form molecular oxygen. This cycle is a continuous process in the upper reaches of the stratosphere.

Question 38.
How Ozone depletion can be controlled?
Answer:
Ozone layer depletion can be controlled by

1. Phase down or ban the use of CFCs (CFC free refrigerants).

2. Minimizing the use of chemicals such as halons and halocarbons.

3. Creating awareness about ozone depleting agents.

Question 39.
What will be effect of Ozone depletion on Earth?
Answer:
UV rays may penetrate deep into the skin and can lead to premature skin aging and wrinkling of skin; suppression of the immune system, skin cancer (melanoma) and chronic effects leading to eye damage. DNA damage can result from free radicals and reactive oxygen and . photons can damage the DNA itself.

Question 40.
Write a brief note on Chipko movement.
Answer:
The Bishnois, who are known conservators of their forest, were inspiration to many people’s participatory movements for Environmental protection in India. The Chipko movement resisted the destruction of forests of India in the 1970s. Sunderlal Bahuguna was the leader of this movement. People in the movement hugged the trees, and prevented felling of trees by contractors.

Question 41.
What do you mean by Ecosan Toilets?
Answer:
About 150 liters of wastewater at an average is generated by an Indian individual daily, and a large amount of it is generated from toilets. Ecological sanitation (EcoSan) is a sustainable system for handling human excreta by using dry composting toilets. EcoSan toilets not only v reduce wastewater generation but also generate the natural fertiliser from recycled human .excreta, which forms an excellent substitute for chemical fertilisers. This method is based on the principle of recovery and recycling of nutrients from excreta to create a valuable supply for agriculture. ‘EcoSan’ toilets are being used in several parts of India and Sri Lanka.

Question 42.
List out the effects of air pollution.
Answer:

1. Affects all organisms as they depend on the atmosphere for respiration.

2. Causes irritation in the throat, nose, lungs and eyes.

3. It causes breathing problems and aggravates existing health conditions such as emphysema and asthma.

4. Contaminated air reduces the body’s defense mechanism and decreases the body’s capacity to fight other infections in the respiratory system.

5. Frequent exposure to polluted air increases the risk of cardiovascular diseases. Breathing air that is filled with fine particulate matter can induce hardening of the arteries, triggering cardiac arrhythmia or even a heart attack.

6. People who exercise outdoors can sometimes be susceptible to adverse effects of air pollution because it involves deeper and faster breathing. Hence it is advisable to walk or jog in the mornings in places with ample tree cover.

7. Gas leaks can be lethal or affect the quality of air in the affected area.

8. CO in the atmosphere interferes with O₂ transport since haemoglobin has greater affinity. for carbon monoxide. At low concentration it causes headache and blurred vision. In higher concentration, it can lead to coma and death.

Question 43.
How air pollution can be controlled?
Answer:
Certain measures help to remove pollutants, reduce their presence or prevent their entry into the atmosphere.

1. Trees are the best remedy for urban particulate and gaseous pollution.

2. Forests act as carbon sinks and lungs of the planet.

3. Catalytic converters in vehicles help to reduce polluting gases drastically.

4. Diesel exhaust filters in automobiles cuts particulates.

5. Electrostatic precipitators reduce release of industrial pollutants.

6. Cost effective air pollution treatment systems like indoor plants and high performance bio filters can improve indoor air quality.

Question 44.
Point out the effects of Noise pollution.
Answer:

1. According to the USEPA (United States Environmental Protection Agency) there are direct links between noise and health. Heart disease, high blood pressure, stress related illness, sleep disruption, hearing loss (deafness), and productivity loss are the problems related to noise pollution.

2. Increased stress and tension, nervousness, irritability, anxiety, depression and panic attacks.

3. Peptic ulcer, severe head ache and memory loss.

4. Marine animals are affected by noise pollution from offshore activities and port activities.

5. Fire crackers frighten animals. Birds are often affected by increased air traffic.

Question 45.
How agrochemicals affect ecosystem?
Answer:

1. May kill beneficial bacteria and soil organisms.

2. Can cause eutrophication in water bodies.

3. Afreet aquatic animals and their productivity.

4. Pesticide containing water, even in trace quantities is unfit for human consumption.

5. Particles (aerosols) and residues of these chemicals cause air pollution.

6. Inhalation of contaminated air can cause respiratory problems.

7. Consumption can lead to poisoning, side effects and after effects.

8. Chemicals can cause skin rashes and irritation of eyes.

9. Many of these chemicals are reported to be carcinogenic.

10. They can trigger hormonal disorders and neurotoxicity.

11. Beneficial insects and animals can be affected.

Question 46.
Categorize the soild waste and their sources.
Answer:

Question 47.
How radioactive waste are managed? Suggest few methods of disposal of radioactive waste.
Answer:
Radioactive waste management involves the treatment, storage, and disposal of liquid, airborne, and solid effluents from the nuclear industry.
Methods of disposal of radioactive wastes are:

1. Limit generation – Limiting the generation of waste is the first and most important consideration in managing radioactive wastes.

2. Dilute and disperse – For wastes having low radioactivity, dilution and dispersion are adopted.

3. Delay and decay – Delay and decay is frequently an important strategy because much of the radioactivity in nuclear reactors and accelerators is very short lived.

4. Concentrate and confine process – Concentrating and containing is the objective of treatment activities for longer-lived radioactivity. The waste is contained in corrosion resistant containers and transported to disposal sites. Leaching of heavy metals and radionuclides from these sites is a problem of growing concern.

Higher Order Thinking Skills (HOTs) Questions

Question 1.
Complete the following:
(a) Smoke + ______ = Smog
Answer:
Fog

Question 2.
What is the unit of measuring ozone thickness?
Answer:
Dobson Unit

Question 3.

List any four adverse effect of noise.
Answer:
High blood pressure Stress related ailments Sleep disruption Hearing impairment

Question 4.
Name the scientist who discovered ozone layer
Answer:
Charles Fabry and Henri Buisson