All Free Forestry MCQs with Answers

• A. H2S
• B. O2
• C. SO2
• D. CO

Explanation: Sulfur dioxide damages leaf tissues and may produce curling, chlorosis and necrosis.

• A. Increases oxygenation
• B. Decreases turbidity
• C. Increases photosynthesis
• D. Increases turbidity deoxygenation

Explanation: Pollution adds suspended matter and organic wastes to water, increasing turbidity while microbial decomposition consumes dissolved oxygen.

• A. More
• B. Less
• C. Equal
• D. Somewhere more somewhere less

Explanation: Sewage contains abundant biodegradable organic matter, so microorganisms require more oxygen to decompose it.

• A. Beggiota
• B. Escherichia
• C. Azospirillium
• D. Chlorella

Explanation: Escherichia coli is used as an indicator of faecal contamination and therefore helps assess sanitary water quality.

• A. China
• B. Europe
• C. Antarctica
• D. Africa

Explanation: The Antarctic ozone hole becomes most pronounced because very low polar temperatures form polar stratospheric clouds that activate…

• A. Roots
• B. Flowers
• C. Stems
• D. Leaves

Explanation: Leaves are directly exposed to polluted air, so gases and particles commonly cause chlorosis, necrosis, and reduced photosynthesis there…

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

Explanation: Carbon monoxide is an air pollutant produced mainly by incomplete combustion, including vehicle exhaust and burning fuels.

• A. Biopollutants
• B. Nuclear blast
• C. Ozone layer
• D. Deforestation

Explanation: The stratospheric ozone layer protects life from harmful ultraviolet radiation, whereas biopollutants, nuclear blasts, and deforestation…

• A. Biotic oxygen deduction
• B. Base of degradation
• C. Biotic oxide demand
• D. Biological oxygen demand

Explanation: BOD means Biological Oxygen Demand, the oxygen required by microorganisms to decompose biodegradable organic matter in water.

• A. Cadmium
• B. Zinc
• C. Lead
• D. All of the above

Explanation: Fungi can bioaccumulate several divalent heavy metals, including cadmium, zinc, and lead, through binding to cell walls and other fungal…

• A. River is not polluted
• B. River is polluted
• C. River is day
• D. None of these

Explanation: A high BOD means microorganisms are consuming large amounts of dissolved oxygen while decomposing organic matter, which is a common sign…

• A. CO2
• B. SO2
• C. H2
• D. CO

Explanation: Hydrogen gas is not ordinarily listed as a conventional air pollutant, whereas carbon dioxide, sulphur dioxide, and carbon monoxide can…

• A. Hole in ozone layer
• B. Decrease in the ozone layer in troposphere
• C. Increase in the thickness of ozone layer in troposphere
• D. Decrease in thickness of ozone layer in stratosphere

Explanation: The ozone hole is a marked thinning or reduction in the concentration of stratospheric ozone, especially over polar regions.

• A. CO
• B. CO2
• C. C
• D. SO2

Explanation: Carbon monoxide is especially poisonous because it binds haemoglobin strongly and prevents blood from carrying oxygen.

• A. Present in water
• B. Utilized by organisms in water
• C. Utilized by micro-organisms for decomposition
• D. Demanded by the producers for the production of food

Explanation: BOD measures the dissolved oxygen consumed by microorganisms while decomposing biodegradable organic matter in water.

• A. DDT
• B. Aluminum foil
• C. Mercury slats
• D. Domestic wastes

Explanation: Domestic wastes commonly contain biodegradable organic material that decomposers can break down.

• 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…