Free Forest Ecology MCQs with Answers

• A. Sewage and industrial effluents
• B. Automobile exhausts and chemicals from industry
• C. Household detergents and pesticides
• D. Sewage and pesticides

Explanation: Automobile exhaust releases carbon monoxide, nitrogen oxides and hydrocarbons, while industries release smoke and toxic chemicals, making…

• A. Aquatic plants
• B. Penicillin
• C. Micro-organisms
• D. Fishes

Explanation: Micro-organisms decompose organic matter and help convert sewage pollutants into simpler, less harmful substances during biological…

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

Explanation: Photochemical smog forms in the atmosphere when sunlight acts on nitrogen oxides and hydrocarbons, producing ozone and other irritants.

• A. 2, 4-D and pesticides
• B. Smoke
• C. Automobile exhaust
• D. Aeroplanes

Explanation: 2,4-D and other pesticides can be carried by runoff into streams and groundwater, where they contaminate aquatic ecosystems.

• A. SO2
• B. N2O
• C. CO
• D. O3

Explanation: Carbon monoxide binds with haemoglobin much more strongly than oxygen does, forming carboxyhaemoglobin and reducing oxygen transport in…

• A. It decreases CO2 concentration
• B. It is carcinogenic
• C. It competes O2 to combine with haemoglobin
• D. It depletes O3 layer

Explanation: CO competes with oxygen for haemoglobin-binding sites and has a much greater affinity for haemoglobin, thereby reducing oxygen delivery to…

• A. Ozone and dust
• B. NH3 and SO3
• C. CO and SO3
• D. NO2 and SO2

Explanation: Sulphur dioxide and nitrogen oxides are oxidised in the atmosphere and react with water to form sulphuric and nitric acids, which fall as…

• A. Chloro-fluoro-carbon
• B. Excess CO
• C. Excess CO2
• D. Low rainfall

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

• A. Malathion
• B. Gamma BHC
• C. Aldrin
• D. None of these

Explanation: Aldrin is a highly persistent organochlorine insecticide that remains in soil for a long time and can form persistent residues.

• A. CO
• B. SO2
• C. Hydrocarbons
• D. CO2

Explanation: In the traditional list of major atmospheric pollutants, CO, SO2 and hydrocarbons are direct air pollutants, whereas CO2 is primarily…

• A. All the above
• B. Increased combustion of oil and coal
• C. Deforestation
• D. Use of refrigerator

Explanation: Refrigerants can release CFCs, fossil-fuel combustion adds CO2, and deforestation both releases stored carbon and reduces its removal by…

• A. Has been responsible for increasing the average global temperature in recent
• B. Helps in checking the penetration of ultra violet rays to earth
• C. Hinders higher rate of photosynthesis
• D. Is advantageous since it supplies O2 for people travelling in jets

Explanation: Stratospheric ozone absorbs much of the Sun's harmful ultraviolet radiation before it reaches Earth's surface.

• A. Sulphur di-oxide
• B. Carbon di-oxide
• C. Carbon monoxide
• D. Nitrogen oxides and fluoro-carbons

Explanation: Fluorocarbons such as CFCs release ozone-destroying chlorine, while nitrogen oxides can also participate in catalytic ozone destruction.

• A. Man
• B. Bacteria
• C. Higher plants
• D. Algae

Explanation: DDT concentration increases at each successive trophic level, so the greatest amount occurs in a top predator such as humans.

• A. Air only
• B. Air, soil and water
• C. Air and soil only
• D. Air and water only

Explanation: DDT can drift through the air during spraying, remain bound to soil, and wash into surface or groundwater.

• A. Petiole but not in lamina
• B. Only mid rib of lamina
• C. Leaf tip and leaf margin
• D. Stems tips only

Explanation: Fluoride injury commonly begins at the leaf tip and progresses along the margins, producing chlorosis followed by necrosis.

• A. Increased incidence of skin cancer
• B. Green house effect
• C. Global warming
• D. Forest fires

Explanation: Stratospheric ozone absorbs harmful ultraviolet-B radiation, so its depletion allows more UV to reach Earth and increases risks such as…

• A. Desertification
• B. Radiation hazard
• C. Deforestation
• D. Gleization

Explanation: Radiation hazard is treated in environmental pollution texts as an especially serious threat because ionising radiation can damage living…

• A. Animals
• B. Plants
• C. Man
• D. Man and animals

Explanation: Human activities are the principal source of modern pollution through industry, transport, agriculture, sewage and waste disposal.

• A. Sewage treatment
• B. Manufacturing electricity
• C. By checking atomic blasts
• D. All of the above

Explanation: Sewage treatment reduces water pollution, controls on atomic blasts reduce radioactive pollution, and cleaner electricity production can…