Environmental Studies · General Awareness

Water Quality and Pollution

1,263 Questions

Water Quality and Pollution examines the sources, mechanisms, and impacts of contaminants in aquatic ecosystems. It covers crucial environmental concepts like eutrophication, biochemical oxygen demand, and thermal pollution. This subject frequently appears in general science and environmental studies sections of various examinations.

Eutrophication CausesThermal Pollution EffectsBiochemical Oxygen DemandSynthetic Fertilizer ImpactsWastewater SourcesAquatic Ecosystem Toxicity

Water Quality and Pollution Questions

Multiple choice

Water is the basis of life, because

Directions: Read the passage and answer the question that follows.

Water is the basis of life. Every animal and every plant contains a substantial proportion of free or combined water in its body, and no kind of physiological activity is possible in which this fluid does not play an essential part. Water is, of course, necessary for animal life, while moisture in the soil is equally imperative for the life and growth of plants and trees, though the quantity necessarily varies enormously with the species. The conservation and utilisation of water is thus fundamental to human life. Apart from artesian water, the ultimate source in all cases is rain or snowfall.

  1. it is seen everywhere on the earth

  2. it is obtained from the sea and rain

  3. it helps all things to exist

  4. it is necessary for the birth, life and growth of all living things
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Without water survival is impossible.

Multiple choice

The wastes dissolved in water are removed as

  1. Feces

  2. Urine

  3. Urea

  4. Ammonia
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When the blood reaches the two kidneys, it contains both useful and harmful substances. The useful substances are absorbed back into the blood. The wastes dissolved in water are removed as urine.

Multiple choice

If the BOD percentage is high, then the

  1. river is polluted

  2. river is not polluted

  3. river is dry

  4. None of the above

  5. -
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

BOD is a measure of the amount of oxygen that is required by the bacteria to degrade the organic components present in water. It is often used as a degree of organic pollution of water.

Multiple choice

Which of the following is a disadvantage of growing 4 to 5 fish species in a single fish pond?

  1. Lack of availability of good quality weeds

  2. Lack of availability of good quality seeds

  3. Competition for food among the fishes

  4. Increase in decomposition of waste
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The practice of growing four to five fish species in a single fish pond is known as composite fish culture. In such systems, these species are selected so that there should not be any competition among them for food as they possess different types of food habits.

Multiple choice

Eutrophication refers to ________.

  1. increase in concentration of the toxicant at successive trophic levels

  2. natural aging of a lake by biological enrichment of its water

  3. shift in ocean temperatures and atmospheric conditions in the tropical Pacific that disrupts weather around the world

  4. presence of large amounts of nutrients in waters also causes excessive growth of planktonic (free-floating) algae

  5. process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and re-radiated in all directions
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Eutrophication is the natural aging of a lake by biological enrichment of its water.

Multiple choice

Which of the following is the result of eutrophication in a lake or pond?

  1. Water absorbs less light, and activate the certain aerobic bacteria.

  2. The level of nitrate and phosphate in the ecosystem increases.

  3. Depletion of oxygen level makes life in water impossible for fish and other living organisms thereby causing death.

  4. Aerobic bacteria depletes the oxygen level, thus only anaerobic bacteria can survive.

  5. Eutrophication in turn favours algal growth and cause algal bloom.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In a polluted pond, the bacteria flourish by depleting the oxygen content. Only the anaerobic bacteria can survive. Depletion of oxygen to such a great extent occurs that it makes life for other organisms impossible.