CBSE Questions for Class 12 Medical Biology Environmental Issues Quiz 10 - MCQExams.com

Match the columns and choose the correct options.
III
(p)e waste(i)Waste clothing
(q)Biodegradable waste(ii)Dirt
(r)Inert waste(iii)Green waste
(s)Composite waste(iv)Irreparable waste
  • p-i, q-ii, r-iv, s-iii
  • p-iv, q-iii, r-ii, s-i
  • p-iii, q-iv, r-i, s-ii
  • p-iv, q-iii, r-i, s-ii
Water above the dissolved $$O_2$$ content may be considered uncontaminated.
  • $$0.8$$ mg/l
  • $$0.008$$ mg/l
  • $$8.0$$ mg/l
  • 8 $$\mu$$g/l
Water pollution of a river is measured by __________.
  • amount of chlorine dissolved in water
  • amount of ozone dissolved in water
  • amount of nitrogen dissolved in water
  • amount of oxygen dissolved in water
Some agro-processing units make an advance agreement with the farmers and decide to purchase the entire production of certain fruits, vegetables and medicinal plants on an agreed upon cost/price. This type of arrangement is known as ______________.
  • import farming
  • crop farming
  • adoptive farming
  • contract farming
If a farmer wishes to increase the productivity of the land, how can it be accomplished?
(A) By the use of chemical inputs.
(B) By excessive use of pesticides/herbicides.
(C) By copious use of water for irrigation.
  • Both (A) and (B)
  • Only (A)
  • Both (B) and (C)
  • Both (A) and (C)
Two bottles were half filled with water from Ganga ('P') and Kaveri ('Q') and kept under identical airtight conditions for 5 days. The oxygen was determined to be 2% in bottle ('P') and 10% in bottle ('Q'). What could because of this indifference?
  • Ganga is more polluted than Kaveri
  • Both the rivers are equally polluted
  • Kaveri is more polluted than Ganga
  • Kaveri has more minerals than Ganga
Water pollination is best assessed by determining.
  • DO and BOD
  • BOD and turbidity
  • Do and acidity
  • BOD and alkalinity
The easiest way to improved the denuded forests of teak in India in to.
  • Apply mycorrhiza
  • Apply fertilizer
  • Add bacterial culture
  • Use green algae
The term 'Phytoremediation' refers to the _________________.
  • Use of plants for removing pollutants from the environment
  • Use of plants as remedies to cure diseases
  • Use of plants for restoration of degraded forests
  • Use of plants in the retention of soil water
The release of $$CO_2$$ into air can cause:
  • Global warming
  • Eutrophication
  • Acid rain
  • Respiratory problems
According to the passage, the argument on use and manufacture of nuclear weapons
  • Does not stand the test of legality
  • Possesses legal strength although it does not have moral standing
  • Is acceptable only on moral grounds
  • Becomes stronger if legal and moral considerations are combined
If a water body have high amount of DDT it's 'Biochemical Oxygen Demand' (B.O.D.) will
  • Decrease
  • Not affected
  • Increase
  • First decrease than increase
A higher biochemical oxygen demand in a particular segment of a river indicates that
  • The segment is free from pollution
  • The segment is highly polluted
  • Aquatic life has started flourishing
  • The river has high number of aquatic animals
Noise cause
  • Headache by constricting blood vessels of the brain
  • Eye strain by constricting the pupil
  • Digestive spasms through anxiety
  • High blood pressure by decreasing cholesterol level in the blood
BOD is ___________ in polluted water and ________in potable water.
  • more, less
  • less, more
  • less in both
  • medium in both
A lake with an inflow of domestic sewage rich in organic waste may result in
  • Drying of the lake vary soon due to algal bloom
  • An increased growth of fishes due to lot of nutrients
  • Death of fish due to lack of oxygen
  • Increased population of aquatic food web organisms
The amount of biodegradable organic matter in sewage water can be estimated by measuring
  • Biochemical Oxygen Demand (BOD)
  • The growth of anaerobic bacteria in water
  • Biogeological oxygen demand
  • The growth of aerobic bacteria in water
BOD of wastewater is amount of
  • total organic matter
  • biodegradable organic matter
  • oxygen evolution
  • oxygen consumption
Given pie-diagram represents the relative contribution of various $$ { GHG }_{ s } $$ to total global warming. Select the correct statements(s) regarding A, B and C.
931212_5a31b66429894465ba7b139bce3fdf2e.png
  • A is the gas which is produced during the combustion of fossil fuels.
  • B are the chemicals which are used as coolants in refrigerators.
  • C is the gas which is the major constituent of biogas.
  • All of these
High concentration of greenhouse gases has resulted in maximum rise of atmospheric temperature in 
  • Tropic region
  • Middle latitude
  • Polar region
  • Temperate region
Match column I with column II and select the correct option from the given codes.

Column IColumn II
ACatalytic converter(i)Used in industries and power plants
BElectrostatic precipitator(ii)Used in automobiles
CEarmuffs(iii)High noise level
DLand fills(iv)Solid wastes
  • A-(i), B-(ii), C-(iii), D-(iv)
  • A-(II), B-(i), C-(iii), D-(iv)
  • A-(iv), B-(III), C-(ii), D-(i)
  • A-(iii), B-(ii), C-(iv), D-(i)
Which of the following isotopes is most dangerous to human beings?
  • Phosphorus-32
  • Strontium-90
  • Caesium-137
  • Iodine-131
Which of the following statements is not correct regarding algal blooms ?
  • Algal blooms are formed by blue-green algae
  • Growth of Eichhornia crassipes causes colouration of water during algal blooms
  • Increased growth of algae causes depletion of $$ { O }_{ 2 } $$ in water
  • Algal blooms cause deterioration of water quality and fish mortality
Phosphate pollution is brought about by
  • Phosphate rocks
  • Automobile exhausts
  • Sewage and phosphate rocks
  • Sewage and agricultural fertilisers
Which of the following statements is correct?   
  • There are working 'EcoSan' toilets in many areas of Kerala and Sri-Lanka
  • Municipal solid wastes are wastes from homes, offices, stores, schools, hospitals, etc. that are collected and disposed by the municipality
  • In a sanitary landfill, wastes are dumped in a depression or trench after compaction and covered with dirt everyday
  • All of these
Which of the following is correct regarding 'El Nino' effect?
  • Temperature rise leads to odd climatic changes
  • Cutting down the use of fossil fuels
  • Planting more trees
  • Slowing down the growth of human population
Which of the following are the correct approaches to reduce global warming ?
(i)   Use of fossil fuels 
(ii)   Improving efficiency of energy usage 
(iii)  Afforestation
(iv)  Increasing growth of human population
  • (i) and (ii)
  • (ii) and (iii)
  • (iii) and (iv)
  • (i), (ii) and (iii)
Read the following statements and select the correct option.

Statement 1: Ozone layer present in the stratosphere protects the living organisms from harmful UV rays coming from the sun by absorbing nearly all of them.

Statement 2: Ozone formed in the troposphere by photochemical reactions as a result of human activities which is harmful to all living organisms.
  • Both statements 1 and 2 are correct.
  • Statement 1 is correct but statement 2 is incorrect.
  • Statement 1 is incorrect but statement 2 is correct.
  • Both statements 1 and 2 are incorrect.
The graph given below represents changes in different ecological parameters due to effluent mixing in a stream. The three lines A, B and C represent 
932200_7206ef57be8749749d452671017bb35c.png
  • A : oxygen concentration, B : biological $$ { O }_{ 2 } $$ demand, c : pollution resistant species
  • A : pollutant, B : aerobic process, c : anaerobic process
  • A : oxygen concentration, b : $$ { CO }_{ 2 } $$ concentration c : temperature
  • A : phosphate concentration, B : nitrate concentration, C : rate of photosynthesis.
Which of the following statements regarding ozone is incorrect ?
  • 'Good ozone' is formed in the lower atmosphere (troposphere) that absorbs harmful UV rays coming from Sun, 'bad ozone' is present in the upper part of atmosphere (stratosphere) that harms plants and animals.
  • The thickness of the ozone in a column of air from the ground to the top of the atmosphere is measured in terms of Dobson units (DU).
  • Recognising the deleterious effects of ozone depletion, an international treaty, known as the Montreal Protocol, was signed at Montreal (canada) in 1987 (became effective in 1989) to control the emission of ozone depleting substances.
  • None of these
Ozone depletion is occurring widely in ______________.
  • Troposphere
  • Stratosphere
  • Ionosphere
  • All of these
Read the given statements and select the correct option. 
Statement 1 : Reforestation is the process of restoring a forest that once existed but was removed at some point of time in the past.
Statement 2 : Reforestation may occur naturally in a deforested area, however it can be speeded up by planting trees with due consideration to biodiversity that earlier existed in that area.
  • Both statements 1 and 2 are correct.
  • Statement 1 is correct but statement 2 is incorrect.
  • Statement 1 is incorrect but statement 2 is correct.
  • Both statements 1 and 2 are incorrect.
Increasing skin cancer and high mutation rate are the result of _______________.
  • Ozone depletion
  • Acid rain
  • $$CO$$ pollution
  • $$ { CO }_{ 2 } $$ pollution
In the event of global warming, which one of the following is most likely to occur?
  • Existing plant and animal communities will move North in response to warming.
  • Agriculture in the prairie provinces will be redeveloped on soils of the Canadian Shield.
  • The anticipated rise in sea level will be caused primarily by the melting of polar ice caps.
  • The decomposition of organic matter in the unfrozen surface layer of polar soils will increase.
The major ozone depleting substance out of the following is _____________.
  • $$ { CFC }{ s } $$
  • $$ { O }_{ 2 } $$
  • Nitrogen
  • All of these
Read the following statements carefully and select the incorrect ones.

(i)  Development of the fertile top-soil takes centuries, but it can be easily removed due to human activities such as over-cultivation, unrestricted grazing, etc.
(ii) Waterlogging results in soil salinity.
(iii)  UV rays are responsible for the degradation of the ozone shield in the atmosphere.
(iv)  Ozone present in the stratosphere acts as a shield absorbing UV radiation coming from the Sun.
(v)  Global warming can be controlled by increasing the use of fossil fuels.
  • (i), (iii) and (v)
  • (iii), (iv) and (v)
  • (iv) and (v)
  • (i), (ii) and (iii)
Consider the following statements regarding the ecosystem which helps in reducing the level of pollution in the atmosphere.
$$1$$. Ecosystems and ecological processes play an important role in maintenance of gaseous composition of the atmosphere, breakdown of wastes and removal of pollutants.
$$2$$. Some ecosystems, especially wetlands have the ability to breaking down and absorb pollutants.
$$3$$. Natural and artificial wetlands are being used to filter effluents to remove nutrients, heavy metals, suspended solids; reduce the BOD (Biological Oxygen Demand) and destroy harmful micro-organisms.
Which of the statements given is/are correct?
  • $$1$$ only
  • $$1$$ and $$2$$
  • $$2$$ and $$3$$
  • All of the above
When we destroy forest, what we are actually destroying?
  • Only food for the wild life
  • Only wild life's habitat
  • Only trees
  • Only environment
Multiple Choice Questions
Global warming can be controlled by
  • Increasing deforestation, reducing efficiency of energy use
  • Reducing deforestation, cutting down use of fossil fuel
  • Reducing deforestation, increasing use of fossil fuel
  • Increasing deforestation, slowing down the growth of human population.
Multiple Choice Questions
BOD in river water
  • Remains unchanged when algal bloom occurs
  • Increases when sewage gets mixed up with river water
  • Has no relationship with concentration of oxygen in water
  • Give a measure for Salmonella in water.
Multiple Choice Questions
BOD is a measure of
  • Industrial wastes passed into water bodies
  • amount of carbon monoxide combined with haemogloblin
  • extent of pollution with organic matter
  • amount of oxygen required by plants during night.
There is a function going on in a house. Loud-speakers are blaring music. What kind of pollution is this? 
  • Air
  • Water
  • Noise
  • Soil
Which of the following is true about organic farming?
  • Organic agriculture relies heavily on chemical fertilisers and toxic pesticides.
  • Organic agriculture depletes the soil and devastates natural eco-systems.
  • Organic agriculture is a whole system of farming that restores, maintains and enhances the ecological balance.
  • All of the above.
Which of the following reasons would support the statement that india will find 'Organic Farming' an attractive proposition?
  • Organic farming requires more labour input than conventional farming, it is employment generating.
  • Organically grown food has more nutritional value than its chemical counterpart and Indians are nutrition conscious.
  • Organic agriculture offers requires costlier agricultural inputs (such as HYV seeds, chemical fertilisers, pesticides etc.)
  • All of the above.
The enhanced growth of water hyacinth in lakes can be due to
  • Disposal of solid wastes in water bodies
  • Availability of more nutrients to the flora of a water ecosystem
  • Discharge of sewage into water bodies
  • All of the above
How are the wild animals affected by cutting of forest?
  • Number decreases
  • Color of skin will be affected
  • Ability of homeostasis will decrease
  • None of these
Which of the following aquatic plant, a major cause of eutrophication in ponds is also called 'Terror of Bengal'?
  • Pistia
  • Euphorbia
  • Eichhornia
  • Selaginella
Ozone layer depletion may lead to which of the following harmful effects in organisms?
  • Skin cancer
  • Cataract
  • Damage to the immune system
  • All of the above
The maximum hole of ozone is found over ______
  • Arctic zone
  • Antarctic zone
  • Tropical zone
  • Subtropical zone
The bio accumulation of pesticides in birds leads to
  • Weakening of nest
  • Egg shell thinning
  • Failure of migration
  • Loss of feather colour
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Practice Class 12 Medical Biology Quiz Questions and Answers