All Free Forestry MCQs with Answers

• A. Moss
• B. Algae
• C. Ferns
• D. Distillated wastes

Explanation: Excess algae can cause an algal bloom; when the algae die, microbes decompose them and consume dissolved oxygen, raising BOD.

• A. DDT
• B. 2,4-D
• C. Bordeaux mixture
• D. DCMU

Explanation: Bordeaux mixture, made from copper sulphate and lime, is a classic contact fungicide used against fungal diseases.

• A. Waste from agricultural fields
• B. Hot chemicals from industries
• C. Waste from mines
• D. Hot water from power plants

Explanation: Thermal pollution occurs when power stations discharge heated cooling water into rivers, lakes, or other water bodies.

• A. DDT killed the pollinating insects along with the pests
• B. DDT disturbed hormonal balance essential for fruit setting
• C. DDT is a growth retardant
• D. DDT inhibited flowering

Explanation: DDT can kill beneficial pollinating insects along with pests, reducing pollination and therefore fruit setting and production.

• A. Automobile exhausts
• B. Radioactive substances
• C. All of the above
• D. Smoke

Explanation: Automobile exhaust, smoke, and radioactive substances can all contaminate the atmosphere. Therefore, the inclusive option is appropriate.

• A. SO2
• B. Hydrocarbons
• C. CO
• D. Fly ash

Explanation: Fly ash is mainly associated with coal combustion in power stations and industrial furnaces, not normal automobile exhaust.

• A. Mutated genes are frequently recessive
• B. Infants are more susceptible to radiation
• C. Susceptibility to radiation increases with age
• D. Contamination of milk supply is not cumulative

Explanation: Radiation-induced mutations may be recessive and remain hidden in the present generation, then appear when inherited by later generations.

• A. Lead
• B. Mercury
• C. Methyl isocyanate
• D. Cyanides

Explanation: Minamata disease resulted from methylmercury contamination of water and aquatic food chains, causing severe neurological damage.

• A. To save the trees from erosion
• B. To safeguard the fruits from large labour population
• C. To protect the orchard from the operation of trucks meant for transporting fruits
• D. To save the trees from poisonous fumes/smoke from the brick chimneys

Explanation: Brick kilns release smoke and pollutants such as sulphur compounds and particulate matter, which can injure foliage and reduce fruit…

• A. SO2
• B. Chlorine/NO2
• C. Oxygen/ozone
• D. Hydrocarbons

Explanation: Sulfur dioxide from industrial emissions can form sulfuric acid and other acidic pollutants, which attack the marble of the Taj Mahal.

• A. Slightly decreases
• B. Increases
• C. Remains unchanged
• D. Decreases drastically

Explanation: Sewage supplies biodegradable organic matter, so microorganisms consume more dissolved oxygen while decomposing it.

• A. Linear alkyl sulphonate
• B. Sulphates and phosphate
• C. Alkyl benzenes sulphonate
• D. None of these

Explanation: Alkyl benzene sulphonate, or ABS, is a persistent detergent surfactant that resists biodegradation and can produce lasting foaming and…

• A. Most probable number
• B. Millions per night
• C. Millennium of probable number
• D. None of these

Explanation: MPN means Most Probable Number, a statistical estimate of viable microorganisms in a water or food sample based on positive and negative…

• A. Phenyl
• B. Chloramines
• C. Chlorine
• D. Ozone

Explanation: Chlorine, chloramines and ozone are established drinking-water disinfectants that inactivate microorganisms.

• A. Asbestos
• B. Sewage
• C. Plastic
• D. All of these

Explanation: Sewage contains organic matter that microorganisms can decompose, so it is biodegradable.

• A. Grease
• B. Eichhornia roots
• C. Asbestos
• D. ABS micelle

Explanation: Asbestos consists of fine, durable fibres that can become airborne and lodge in the lungs, causing diseases such as asbestosis and…

• 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…