Assignments Class 12 Biology Environmental Issues

Please refer to Assignments Class 12 Biology Environmental Issues Chapter 16 with solved questions and answers. We have provided Class 12 Biology Assignments for all chapters on our website. These problems and solutions for Chapter 16 Environmental Issues Class 12 Biology have been prepared as per the latest syllabus and books issued for the current academic year. Learn these solved important questions to get more marks in your class tests and examinations.

Environmental Issues Assignments Class 12 Biology

Objective Questions

Question. Electrostatic precipitators can remove how much percentage of particutate matter present in exhaust from a thermal power plant –
(a) 90%
(b) 95%
(c) 99%
(d) 100%

Question. Which of the following is not associated with catalytic convertors –
(a) Conversion of unburnt hydrocarbon to CO₂ & H₂O
(b) Conversion of CO to CO₂
(c) Conversion of NOx to N₂
(d) Conversion of SO₂ to S

Question. Motor vehicles equipped with catalytic convertor should use unleaded petrol because –
(a) Lead in petrol inactivates the catalyst
(b) Lead in petrol act as catalyst
(c) Lead in petrol start to burn along petrol
(d) Lead in petrol leads to checking burning of petrol

Question. Domestic sewage primarily contains –
(a) Suspended solid
(b) Colloidal matter
(c) Biodegradable matter
(d) Dissolved matter

Question. About highly sewage polluted water, what is true –
(a) High DO and BOD
(b) High DO and less BOD
(c) Low DO and low BOD
(d) Low DO and high BOD

Question. In 1990s what was the rank of Delhi among the 41 most polluted cities of the world –
(a) 1st
(b) 2nd
(c) 3rd
(d) 4th

Question. What was the main step taken in Delhi to control air pollution after Public interest litigation (PIL) filed in Supreme court. –
(a) Reduction in vehicles
(b) Use of CNG in buses instead of Diesel
(c) Use of catalytie convertor
(d) Plantation

Question. All the buses of Delhi were converted to run on CNG by The end of 2002. Why CNG is better than Diesel-
(a) CNG burns most efficiently
(b) Little of it is left unburnt
(c) Inactivate catalyst of catalytical convertor
(d) Both (a) and (b)

Question. The Government of India through a new auto fuel policy has laid out a road map to cut down vehicular pollution in Indian cities. Most stringent norms for fuels means-
(a) Steadily reducing the sulphur content in petrol
(b) Steadily reducing the aromatics content in petrol
(c) Steadily reducing the sulphur and aromatics content in petrol and diesel
(d) Steadily reducing the particulated matter in petrol and Diesel

Question. With which polyblend was mixed to lay roads. Which show increased water repellant properties –
(a) Polysterene
(b) Bitumen
(c) Polyethylene
(d) Plastic

Question. e – wastes generated in developed countries, is used by developing countries for recovery of –
(a) Gold
(b) Nickel
(c) Copper
(d) All the above

Question. According Euro-III norms, what should be the level of sulphur in diesel and petrol respectively –
(a) 150 ppm & 350 ppm
(b) 350 ppm & 150 ppm
(c) 250 ppm & 350 ppm
(d) 350 ppm & 250 ppm

Question. According to Euro-III norms, In petrol or diesel aromatic hydrocarbons are to be contained at 42 percent and goal of it to bring down the level of sulphur –
(a) 30%
(b) 40%
(c) 42%
(d) 35%

Question. The Bharat Stage-III, norms for reducing the level of vehicular pollutant, is equivalent to –
(a) Euro-I norms
(b) Euro-II norms
(c) Euro-III norms
(d) Euro-IV norms

Question. Pollution is undesirable changes in physical, chemical and biological properties. Which among the following is not air pollution induced plant injury –
(a) Reduced growth and yield
(b) Premature death of plant
(c) Clogging of Stomata
(d) Oxygen binding ability

Question. Air (Prevention and control of pollution) act 1981 was amended in 1987 to include __________ as an air pollutant. –
(a) Particulated matter
(b) Hydrocarbons
(c) Noise
(d) Radioactive pollutants

Question. The ozone hole over Antarctica develops each year between –
(a) Late August and early October
(b) Early August and late October
(c) Early October and early December
(d) Late October and late December

Question. Which of the following is not a result of water logging-
(a) Deposition of salt crust on land
(b) Collection of salts around root
(c) Damage to agriculture
(d) Leaching of salts

Question. The Specific intensity of noise, which may damage ear drums and causes permanently impairing hearing ability is –
(a) Equal and less than 150 dB
(b) Equal and more than 150 dB
(c) Less than 20 dB
(d) Less than 80 dB

Question. Noise as one of the important air pollutant is not responsible for –
(a) Sleeplessness
(b) Increase heart beating
(c) Altered breathing pattern
(d) Decreased oxygen carrying capacity

Question. To safe guard our water resources, water (prevention and control of pollution) act was came in force –
(a) 1971
(b) 1972
(c) 1974
(d) 1981

Question. According to National forest policy (1988) of India has recommended 33% forest cover for plains and_______% area for hills.-
(a) 30%
(b) 19.4%
(c) 67%
(d) 76%

Question. Montreal Protocol was come in action from –
(a) 1987
(b) 1988
(c) 1989
(d) 1992

Question. Which among the following is not a result of Deforestration –
(a) Enhanced carbondioxide concentration
(b) loss of biodiversity
(c) Ozone depletion
(d) Disturbed hydrological cycle

Question. According to Euro-III norms, which among the following standard is not true –
(a) Sulphur should be controlled at 350 ppm in Diesel 
(b) Sulphur should be controlled at 150 ppm in petrol
(c) Aromatic hydrocarbons should be contained at 42 percent
(d) Sulphur content should be controlled at 50 ppm in petrol and diesel

Statement Type Questions

Question. Pollution in big cities can be controlled to a large extent by
(i) improving traffic condition and road.
(ii) road side plantation
(iii) proper disposal of garbage and domestic as well as municipal wastes.
(iv) cannot be controlled
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (i) and (iv)
(d) all of these

Question. Mark the statement that describes the eco-friendly disposal of municipal solid- waste.
(a) It should be burnt to completion.
(b) It should be dumped in open waste land.
(c) It should be dumped in sanitary landfills.
(d) It should be sorted out into bio-degradable, non- bio-degradable and recyclable wastes and treated separately.

Question. ‘EcoSan’ toilets, being used in Kerala and Sri Lanka are hygienic and cost effective solution to human waste disposal. Mark the correct statement regarding EcoSan.
(a) Recycled human waste from this can be used as a natural fertilizer.
(b) They are called composting toilets.
(c) They do not depend on water for the disposal of excreta.
(d) All of the above

Question. Which of the following statement (s) is/are correct about noise pollution?
(a) It is an undesired high level of sound.
(b) It is measured in dB.
(c) It can cause damage to heart, increase blood cholesterol and even raise blood pressure etc.
(d) All of the above

Question. Mark the correct statement.
(a) The major contribution in green house gases is of CH₄.
(b) Global warming is because of ozone depletion.
(c) When organic waste enters into a water body its BOD increases.
(d) All of the above

Question. Which of the following statement is incorrect?
(a) Noise pollution does not leave any residue in the environment.
(b) Noise pollution creates nervous disorders.
(c) Plants are efficient absorbers of noise of low frequency.
(d) Loss of hearing is a common disorder .

Assertion/Reason Type Questions

In the following questions, a statement of Assertion is followed by a statement of Reason.
(a) If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.
(b) If both Assertion and Reason are true but the Reason is not the correct explanation of the Assertion.
(c) If Assertion is true but Reason is false.
(d) If both Assertion and Reason are false.

Question. Assertion : Methane, component of green house gases, contributing to global warming is about 20 percent.
Reason : Introduction of multi-point fuel injection engines in automobiles has decreased methane content in the exhausts.

Question. Assertion : Presently, the global atmosphere is warming up.
Reason : The depletion of stratospheric ozone layer has resulted in increase in ultraviolet radiations reaching the earth.

Question. Assertion : Eutrophication shows increase in productivity in water.
Reason : With increasing eutrophication, the diversity of the phytoplankton increases.

Critical Thinking Type Questions

Question. In clean water, the concentration of
(a) BOD is low but DO is high.
(b) Both BOD and DO are high.
(c) BOD is high but DO is low.
(d) Both BOD and DO are low.

Question. Fishes die by sewage because
(a) of its bad smell.
(b) it replaces food material of fishes.
(c) it increases oxygen competition among fishes.
(d) CO₂ is mixed in large amounts in water.

Question. Two lakes, A and B are identical in all aspects except that lake A has higher temperature. Which of the following is true ?
(a) A has higher rate of oxygen dissolution.
(b) B has higher rate of oxygen dissolution.
(c) Oxygen dissolution of both is the same.
(d) Both the lakes have same BOD.

Question. Which constituent of the atmosphere is likely to change if the forest cover is removed ?
(a) O₂ level is increased
(b) CO₂ level is increased
(c) O₂ level is significantly increased
(d) CO₂ level is significantly decreased

Question. Which of these is not an advantage of CNG over diesel?
(a) Burns more efficiently.
(b) It is cheap.
(c) Cannot be siphoned off by thieves.
(d) Easy to lay down pipelines for delivery.

Question. Which of the following steps is not taken for reducing vehicular pollution?
(a) Use of unleaded petrol.
(b) Use of high-sulphur petrol and diesel.
(c) Use of catalytic converters in vehicles.
(d) Application of stringent pollution-level norms for vehicles.

Question. Which of the following statements is/are correct about ‘Eco San’ toilets?
(a) It is a sustainable system for handling human excreta or faecal matter by using dry ‘composting toilets’.
(b) These are very useful for the rural areas where sewer systems are not possible.
(c) These toilets are hygienic, efficient, practical & most effective for the disposal of human waste.
(d) All of the above

Question. The effect of todays radioactive fall out will be harmful to children of future generation because
(a) infants are more susceptible to radiations.
(b) susceptibility to radiation increase with age.
(c) mutated genes are frequently recessive.
(d) contamination of milk supply is not cumulative.

Question. Which of the following is not one of the prime health risks associated with greater UV radiation due to depletion of stratospheric ozone?
(a) Increased liver cancer
(b) Increased skin cancer
(c) Damage to eyes
(d) Reduced immune system

Question. The most adverse effect of radioactive pollutant is
(a) gene mutation
(b) hepatitis
(c) polio
(d) T.B.

Question. Global warming can be controlled by
(a) reducing reforestation, increasing the use of fossil fuel.
(b) increasing deforestation, slowing down the growth of human population.
(c) increasing deforestation, reducing efficiency of energy usage.
(d) reducing deforestation, cutting down use of fossil fuel

Question. Which one of the following is not correct as regards to the harmful effects of particulate matter of the size 2.5 micro meters or less?
(a) It can be inhaled into the lungs.
(b) It can cause respiratory problems.
(c) It can directly enter into our circulatory system.
(d) It can cause inflammation and damage to the lungs.

Question. In the coming years, skin related disorders will be more common due to
(a) air pollution
(b) use of detergents
(c) water pollution
(d) depletion of ozone layer

Question. In an aquatic ecosystem, maximum biomagnification is seen among
(a) fishes
(b) phytoplanktons
(c) microscopic plant
(d) zooplanktons

Question. The presence of ozone in the atmosphere of earth
(a) is advantageous since it supplies O₂ for people travelling in jets.
(b) helps in checking the penetration of ultraviolet rays to earth.
(c) hinder higher rate of photosynthesis.
(d) has been responsible for increasing the average global temperature in recent years.

Matching Type Questions

Question. Match column-I with column-II and select the correct option.

Column-I	Column-II
A. Catalytic converter	I. Particulate matter
B. Electrostatic precipitator	II. Carbon monoxide and  nitrogen oxides
C. Earmuffs	III. High noise level
D. Land fills	IV. Solid wastes

(a) A – I, B – II, C – III, D – IV
(b) A – II, B – I, C – III, D – IV
(c) A – IV, B – III, C – II, D – I
(d) A – III, B – II, C – IV, D – I

Question. Match column-I with column-II and select the correct option.

Column-I (Organisms)	Column-II (Concentration of DDT)
A. Zooplankton	I. 2 ppm
B. Small fish	II. 0.04 ppm
C. Large fish	III. 0.5 ppm
D. Fish-eating birds	IV. 25 ppm

(a) A – II; B – III; C – I; D – IV
(b) A – III; B – II; C – I; D – IV
(c) A – II; B – III; C – IV; D – I
(d) A – II; B – I; C – III; D – IV

Question. Which one of the following pairs is mismatched?
(a) Fossil fuel burning – release of CO₂
(b) Nuclear power – radioactive wastes
(c) Solar energy – green house effect
(d) Biomass burning – release of CO₂

Question. Match column-I with column-II and choose the correct option.

Column-I	Column-II
A. Colloidal materials	I. Typhoid, Jaundice, Cholera
B. Water-borne diseases	II. Irreparable computes and other electronic goods
C. E-wastes	III. Faecal matter bacteria, cloth and paper fibres
D. Manure	IV. Troposphere
E. Bad ‘Ozone’	V. Cattle excreta (dung)

(a) A – I, B – III, C – II, D – V, E – IV
(b) A – III, B – I, C – V, D – II, E – IV
(c) A – III, B – I, C – II, D – V, E – IV
(d) A – III, B – I, C – V, D – IV, E – II

Diagram Type Questions

Question. Which of the following figures shows correct relative contribution of greenhouse gases to global warming?

Question. The diagram below shows the effect of polluting a river with untreated whey. What does graph X represent?

(a) Bacterial count.
(b) Number of fish.
(c) Mass of curds.
(d) Concentration of rennet.

Question. What does ‘x’ indicate in the given figure?

(a) Greenhouse effect
(b) El Nino Effect
(c) Ozone hole
(d) Marsh meadow stage