Free Forest Ecology MCQs with Answers

• A. Heterosphere
• B. Stratosphere
• C. Homosphere
• D. Troposphere

Explanation: The troposphere is the lowest atmospheric layer, extending from the ground upward and containing most weather and atmospheric pollutants.

• A. 245 ppm
• B. 275 ppm
• C. 215 ppm
• D. 230 ppm

Explanation: Atmospheric carbon dioxide in the late nineteenth century was approximately 275 ppm, close to the pre-industrial level of about 280 ppm.

• A. 400 ppm
• B. 500 ppm
• C. 475 ppm
• D. 450 ppm

Explanation: Many standard environmental projections estimated atmospheric CO2 at about 450 ppm by 2040, compared with roughly 280 ppm before…

• A. 1885
• B. 1895
• C. 1905
• D. 1910

Explanation: Classical, or London-type, smog was first recognised in London around 1905 and results mainly from coal smoke, sulphur dioxide and fog.

• A. Growth of organism due to food consumption
• B. Increase in population size
• C. Increase in the concentration of non-degradable pollutants as they pass through food chain
• D. Blowing up of environmental issues by man
• E. Decrease in population size

Explanation: Biomagnification is the progressive increase in concentration of persistent, non-biodegradable pollutants at successive trophic levels.

• A. 1933
• B. 1943
• C. 1953
• D. 1963

Explanation: Photochemical smog was first clearly observed in Los Angeles in 1943, when sunlight acted on nitrogen oxides and hydrocarbons to form…

• A. CFC, CH4 and SO2
• B. Sulphates of Na, Ca and Fe
• C. Fly ash
• D. All of these

Explanation: Fly ash is the fine particulate residue released when coal or other solid fuels are burned in industrial furnaces, and it can contaminate…

• A. Photochemical smog
• B. Wet acid deposition
• C. Industrial smog
• D. Dry acid deposition

Explanation: Nitrogen oxides can be converted into nitric acid vapour and nitrate particles that settle directly onto surfaces as dry acid deposition.

• A. Air pollution released from oil refinery
• B. Degradation of marble due to high temperature
• C. Riparian erosion
• D. Discharge of industrial waste in Yamuna river

Explanation: Sulphur dioxide and other pollutants from the nearby oil-refining and industrial belt formed acids that discoloured and damaged the Taj…

• A. Noise of traffic
• B. Shock waves
• C. Noise of siren
• D. Unhearable sound

Explanation: A sonic boom is the intense sound produced when a supersonic object generates shock waves that reach an observer.

• A. Chlorides
• B. Cyanides
• C. Nitrates
• D. Fluorides

Explanation: Excess nitrate in drinking water can be converted to nitrite, which interferes with haemoglobin's oxygen-carrying ability and causes…

• A. One test every 20th day
• B. One test every 13th day
• C. One test every 11th day
• D. One test every 9th day

Explanation: The combined testing history of the five recognized nuclear powers gives an average close to one test every nine days.

• A. Riccinus communis
• B. Iberis amara
• C. Cynodon dactylon
• D. All of these

Explanation: Ricinus communis, the castor-oil plant, contains toxic compounds such as ricin and has insecticidal activity.

• A. Zr95, Mn54
• B. Cr51, Cu64
• C. Sr90, I131
• D. All of these

Explanation: Strontium-90 and iodine-131 are important radioactive fission products released during nuclear fission.

• A. Eichhornia crassipes
• B. Lemna pancicostata
• C. Entamoeba histolytica
• D. Escherichia coli

Explanation: Escherichia coli is used as an indicator of faecal contamination because it normally occurs in the intestines of humans and other…

• A. Bones
• B. Thyroid
• C. Kidneys
• D. Muscles

Explanation: Strontium-90 behaves chemically like calcium, so it is absorbed into the skeleton and deposited in bones.

• A. 1-5 db
• B. 35-45 db
• C. 40-60 db
• D. 65-75 db

Explanation: A sound level of about 35 to 45 dB is commonly classified as moderately quiet in environmental-noise tables.

• A. 120 db
• B. 150 db
• C. 180 db
• D. 240 db

Explanation: A rocket launch produces extremely intense sound, commonly cited at about 180 dB near the source.

• A. Cyanides and phenols
• B. Chlorides and fluorides
• C. Carbonates and sulphides
• D. Bicarbonates and chlorides

Explanation: Wastewater and effluents from steel and coking operations may contain cyanides and phenolic compounds, which are major toxic pollutants.

• A. 120-170 db
• B. 90-160 db
• C. 100-130 db
• D. 100-160 db

Explanation: The cited environmental-noise table places London’s overall noise level at approximately 100 to 160 dB.