Free Forest Ecology MCQs with Answers

• A. Increases
• B. Decreases
• C. Remains the same
• D. Is no measure of pollution

Explanation: BOD measures the oxygen microorganisms need to decompose organic pollutants.

• A. Mineralization
• B. Eutrophication
• C. Oligotrophication
• D. All of these

Explanation: Eutrophication is the enrichment of a water body with nutrients, especially nitrates and phosphates.

• A. Aldrin
• B. Lindane
• C. Chloremphenicol
• D. Chlordane

Explanation: Chloramphenicol is an antibiotic, not a commonly used pesticide. Aldrin, lindane and chlordane are organochlorine pesticides, although…

• A. BOD much higher than COD
• B. BOD slightly higher than COD
• C. COD slightly higher than BOD
• D. COD much higher than BOD

Explanation: COD includes oxygen needed to oxidize both biodegradable and non-biodegradable substances, whereas BOD measures mainly biodegradable…

• A. Caesium oxide deposition
• B. Chemical oxygen demand
• C. Chemistry of depositions
• D. Control of diesel

Explanation: COD means Chemical Oxygen Demand, the oxygen required to chemically oxidize oxidizable substances in water.

• A. Thousands
• B. Hundreds
• C. Billion
• D. Millions

Explanation: Human faeces contain Escherichia coli in very large numbers, commonly expressed as billions of cells per gram or millilitre of excreta.

• A. Always an unfavourble alteration
• B. Always a favourable change
• C. Rarely a favoruable alteration
• D. Usually an unfavourable change

Explanation: Pollution is conventionally defined as an undesirable or unfavourable change in the physical, chemical or biological characteristics of…

• A. Warming of earth
• B. Trapping of UV rays
• C. Cooling of earth
• D. Production of cereals

Explanation: The greenhouse effect is the warming of Earth when gases such as carbon dioxide, methane and water vapour absorb outgoing infrared…

• A. Pyridine aceto-nitrite
• B. Peroxy acyl nitrite
• C. Peroxy acetyl nitrate
• D. Peroxy aceto-nitrile

Explanation: PAN is peroxyacetyl nitrate, a secondary pollutant formed during photochemical smog when nitrogen oxides and hydrocarbons react in…

• A. Ethylene
• B. PAN
• C. N2O
• D. 3.4 Benzpyrene

Explanation: 3,4-benzpyrene, more commonly called benzo[a]pyrene, is a carcinogenic polycyclic aromatic hydrocarbon found especially in smoke and…

• A. Both (a) & (b)
• B. Electrodialysis
• C. Reverse osmosis
• D. None of these

Explanation: Reverse osmosis removes many dissolved organic compounds and ions, while electrodialysis is particularly useful for removing ionisable…

• A. New York type smog
• B. Los Angeles type smog
• C. Tokyo type smog
• D. California type smog

Explanation: Photochemical smog is classically called Los Angeles-type smog because it was extensively studied there under intense sunlight, high…

• A. Increase in productivity
• B. Destruction of phytoplanktons
• C. Inundation of coastal towns
• D. Melting of polar ice

Explanation: A 5°C global rise would rapidly threaten frozen regions, making melting of polar ice an immediate hazard.

• A. Hydrocarbons only
• B. Hydrocarbons and SO2
• C. Hydrocarbons and N2O
• D. Particulate matter and SO2

Explanation: Classical, or sulfurous, smog is associated with coal burning and contains sulfur dioxide along with smoke and particulate matter.

• A. Barium salts
• B. Cobalt salts
• C. Silicon oil
• D. Calcium salts

Explanation: Barium salts have been used as fuel additives to help reduce smoke and particulate emissions from engines.

• A. At night
• B. In the mid day
• C. In early morning
• D. At evening

Explanation: Photochemical smog develops when sunlight drives reactions between nitrogen oxides and hydrocarbons, so it is usually most prominent…

• A. Tanneries
• B. Paper factories
• C. Chemical factories
• D. Sugar mills

Explanation: Industrial chemical discharges are a major source of pollution in the Periyar River, particularly from chemical industries in its basin.

• A. Hill reaction
• B. ATP synthesis
• C. CO2 fixation
• D. Glycolysis

Explanation: PAN damages chloroplast function by inhibiting the light-dependent electron-transfer process, commonly described as blocking the Hill…

• A. USA/Korea
• B. Japan
• C. China
• D. Russia

Explanation: Minamata disease was first recognized around Minamata Bay in Japan, where industrial methylmercury contamination caused severe…

• A. Ethylene
• B. N2O
• C. Ozone
• D. PAN

Explanation: Ozone is a major phytotoxic air pollutant, and tobacco and tomato are commonly used as sensitive plant indicators of ozone injury.