Free Man and His Environment MCQs with Answers

261. Identify the correctly matched pair:

• A. Basal convention - Biodiversity conservation
• B. Kyoto protocol ­ - Climatic change
• C. Montreal protocol ­- Global warming
• D. Ramsar convention - Ground water pollution

Explanation: The Kyoto Protocol is an international treaty aimed at addressing climate change by reducing greenhouse gas emissions which was adopted at the third session of the Conference of Parties (CoP -­ 3) to the UNFCCC (United Nations Framework Convention on Climate Change) in 1997, in Kyoto, Japan.

262. Lead concentration in blood is considered alarming if it is:

• A. 20 mg / 100 m
• B. 30 mg / 100 ml
• C. 4 -­ 6 mg / 100 ml
• D. 10 mg / 100 ml.

Explanation: Lead (Pb) is released by the combustion of petrol because tetraethyl lead is used as an antiknocking in petrol. This lead is very harmful and causes plumbism or lead poisoning, which disturbs the nervous system, liver, kidneys in adults and also causes brain damage in children. About 150 to 400 mg of lead is stored in the body of an average adult and blood levels average about 25 mg/100 ml. An increase to 70 mg/100 ml of blood is generally associated with clinical symptoms. Hence a level of 30 mg/100 ml should be considered alarming.

263. A common indicator organism of water pollution is:

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

Explanation: E.coli is the most common indicator of water pollution. It naturally occurs in the intestines of human beings and animals. They are commonly found in sewage and if E.coli are detected in water, they are indicative of faecal contamination. This is a serious health risk and that water should not be used for drinking.

264. Fluoride pollution mainly affects the:

• A. Brain
• B. Heart
• C. Teeth
• D. Kidney

Explanation: Fluorides are given out during the refining of materials. Fluorides cause fluorosis. It is a disease that is defined by mottling of teeth, abnormal bones that are liable to fracture because fluorine replaces Ca2+ and makes the bones brittle. High levels of fluoride in drinking water can have adverse effects on dental and skeletal health. In areas with excessive fluoride in water, it can lead to dental fluorosis, a condition characterized by discolored, pitted, or mottled tooth enamel. In severe cases, excessive fluoride intake can result in skeletal fluorosis, which can cause joint pain, bone deformities, and reduced mobility.

265. Escherichia coli is used as an indicator organism to determine pollution of water with:

• A. Heavy metals
• B. Faecal matter
• C. Industrial effluents
• D. Pollen of aquatic plants

Explanation: E.coli is the most common indicator of water pollution. It naturally occurs in the intestines of human beings and animals. They are commonly found in sewage and if E.coli are detected in water then it indicates faecal contamination. So if E.coli are detected in drinking water it indicates a serious health risk and that water should not be used for drinking.

266. Which of the following is absent in polluted water?

• A. Hydrilla
• B. Water hyacinth
• C. Larva of stone fly
• D. Blue green algae

Explanation: Stoneflies are extremely sensitive to water pollution. Their presence in a water body is an indicator of good water quality, while their absence may signal pollution or habitat degradation. Their sensitivity makes them valuable for assessing the health of freshwater ecosystems.

267. The Minamata disease in Japan was caused through the pollution of water by:

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

Explanation: Mercury is changed to water soluble dimethyl mercury which undergoes biomagnification. Eating poisoned animals causes deformity known as Minamata disease (first reported in 1952 due to eating of fish captured from Hg-diarrhea­contaminated Minimata Bay of Japan) which is characterized by diarrhoea, hemolysis, impairment of various senses, numbness of lips, tounge, limbs, deafness, blurring of vision, mental dearrangement, meningitis and death.

268. D.D.T. is:

• A. Not a pollutant
• B. An antibiotic
• C. A non­-degradable pollutant
• D. A biodegradable pollutant

Explanation: DDT is non­biodegradable and is not metabolized within the body of an organism. It accumulates in the fat tissues therefore its concentration goes on increasing from one trophic level to another of a food chain, the highest amount being present in top consumer i.e., it shows biomagnification. In an aquatic food chain, the seagull is the top carnivore therefore it will possess the highest concentration of DDT.

269. Which of the following organism is likely to have more concentration of D.D.T. in its body?

• A. Top carnivore
• B. Primary producers
• C. Herbivores
• D. Carnivores

Explanation: DDT is non-­biodegradable and is not metabolized within the body of an organism, rather it accumulates in the fat tissues. Therefore its concentration goes on increasing from one trophic level to another of a food chain, the highest amount being present in the top consumer i.e., it shows biomagnification. In an aquatic food chain, the seagull is the top carnivore therefore it will possess the highest concentration of DDT.

270. Which of the following is a pollution related disorder?

• A. Silicosis
• B. Pneumonicosis
• C. Fluorosis
• D. Leprosis

Explanation: Fluorides are given out during the refining of materials. Fluorides cause fluorosis. It is a disease that is defined by mottling of teeth, abnormal bones that are liable to fracture because fluorine replaces Ca2+ and makes the bones brittle.