Free Forest Ecology MCQs with Answers

• A. Organic matter
• B. Microbes
• C. Both (a) & (b)
• D. None of these

Explanation: BOD depends on organic matter because it provides the material for decomposition, and on microbes because they consume oxygen while…

• A. Soil pollutant
• B. Air pollutant
• C. Water pollutant
• D. Noise pollutant

Explanation: Lead has traditionally been classified as an air pollutant because combustion of leaded petrol and industrial emissions release lead…

• A. Acid rain
• B. Smog
• C. Both (a) & (b)
• D. None of these

Explanation: Acid rain and smog can spread across areas larger than their emission sources and are therefore commonly treated as regional forms of…

• A. Industrial effluents
• B. Phytoplankton
• C. Ammonia
• D. Smoke

Explanation: Industrial effluents introduce chemicals, heavy metals and organic wastes directly into water bodies, making them a major cause of water…

• A. CO
• B. CO2
• C. NO2
• D. PO4

Explanation: Carbon dioxide is a major greenhouse gas because it absorbs outgoing infrared radiation and contributes to atmospheric heat retention.

• A. Hardness of water
• B. Industrial pollution
• C. Sewage pollution
• D. Presence of chlorine in water

Explanation: E. coli is a faecal indicator organism, so its high concentration signals contamination by sewage or other faecal waste.

• A. 10-20 dB
• B. 120-150 dB
• C. 90-12 dB
• D. 40-60 dB

Explanation: Normal conversation is usually about 40 to 60 dB at ordinary speaking distance.

• A. Global warming
• B. The UV radiations reach the earth
• C. Greenhouse effect
• D. Acid rain

Explanation: Depletion of the ozone layer allows more harmful ultraviolet radiation, especially UV-B, to reach Earth’s surface.

• A. Hg
• B. Cd
• C. Pb
• D. Cu

Explanation: Lead is the characteristic hazardous metal in automobile exhaust, especially from vehicles using leaded petrol, and it affects the nervous…

• A. Sulphur di-oxide
• B. Carbon di-oxide
• C. Chloro-fluoro-carbon
• D. Smog

Explanation: Chlorofluorocarbons release chlorine radicals in the stratosphere, and these radicals catalytically destroy ozone.

• A. Very costly
• B. Not available
• C. Inflammable
• D. Not degraded easily

Explanation: DDT is banned or restricted because it is highly persistent, accumulates in body tissues and becomes concentrated through food chains.

• A. Thermal power plant
• B. Hydroelectric power plant
• C. Radioactive power plant
• D. Automobile

Explanation: In the conventional comparison used in pollution MCQs, hydroelectric power produces no direct smoke or combustion emissions during…

• A. Hydrocarbons, SO2 and CO2
• B. Smoke, peroxyacetyl nitrate and SO2
• C. Ozone, peroxyacetyl nitrate and No2
• D. Hydrocarbons, ozone and SO2

Explanation: Photochemical smog is produced when nitrogen oxides and hydrocarbons react in sunlight, forming ozone and peroxyacetyl nitrate.

• A. Fungi
• B. Fishes
• C. Algae
• D. Lichen

Explanation: Lichens are highly sensitive to sulphur dioxide because they absorb water and dissolved pollutants directly over their surface, with no…

• A. NO2 and hydrocarbons
• B. SO2 and CO2
• C. Carbon di-oxide and NO2
• D. Hydrocarbons and CFCs

Explanation: The primary ingredients of photochemical smog are nitrogen dioxide and reactive hydrocarbons, which sunlight converts into secondary…

• A. CO
• B. SO2
• C. Ozone
• D. Flourides

Explanation: Ultraviolet radiation splits oxygen molecules, and the resulting oxygen atoms combine with O₂ to form ozone (O₃).

• A. Sulphur dioxide
• B. Nitrogen di-oxide
• C. Carbon monoxide
• D. Carbon di-oxide

Explanation: Carbon dioxide is a major greenhouse gas released by fossil-fuel burning, deforestation, and other human activities.

• A. World environment day
• B. World forest day
• C. World red cross day
• D. World food day

Explanation: World Environment Day is observed annually on 5 June to promote awareness and action on environmental protection.

• A. Green vegetation of an area
• B. Micro-organisms
• C. Food crop
• D. None of these

Explanation: Microorganisms often show pollution effects first because they live directly in soil, water, and decomposing material and respond rapidly…

• A. Sulphur dioxide
• B. Nitrogen di-oxide
• C. Global warming
• D. Population explosion

Explanation: Population explosion increases demand for land, housing, energy, and resources, leading to deforestation, urbanization, and greater…