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 zoology environmental factors environmental factors and their measurements climate factors marine life

Marked temperature changes in aquatic environment can affect 

  1. availability of food

  2. growth of plants

  3. breedingofanimals

  4. the amount of oxygen dissolved in water
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Aquatic organisms are used to a certain range of temperature in the water-body where they live. A sudden marked change in this temperature can be dangerous for them. It affects breeding of aquatic animals. The eggs and larvae of various animals are particularly susceptible to temperature changes.

Multiple choice chemistry air and water pollution control smoke, dust and other air pollutants, acid rain air pollutants and its effects air and air pollution

Ammonia is most harmful for:

  1. humans

  2. animals

  3. aquatic organisms

  4. plants
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The toxicity of ammonia solutions does not usually cause problems for humans and other mammals, as a specific mechanism exists to prevent its build-up in the bloodstream. Ammonia is converted to carbamoyl phosphate by the enzyme carbamoyl phosphate synthetase, and then enters the urea cycle to be either incorporated into amino acids or excreted in the urine. Fish and amphibians lack this mechanism, as they can usually eliminate ammonia from their bodies by direct excretion. Hence ammonia even in dilute solutions is very harmful for aquatic organisms.

Multiple choice biology option c: ecology and conservation hotspots and methods of conservation biodiversity: conservation conservation of biodiversity

Statement 1 : BOD represents the amount of dissolved oxygen that would be consumed if all the organic matter in one litre of water were oxidised by microorganisms.
Statement 2 : High value of BOD indicates that water is highly polluted by organic matter.

  1. Both statements 1 and 2 are correct.

  2. Statement 1 is correct but statement 2 is incorrect.

  3. Statement 1 is incorrect but statement 2 is correct.

  4. Both statements 1 and 2 are incorrect.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
BOD is the amount of dissolved oxygen needed by aerobic biological organisms to break down organic material present in a given water sample at certain temperature.
High BOD indicates the water is highly polluted because the dissolved oxygen is  already consumed by bacteria.
So, the correct option is 'Both statements 1 and 2 are correct'
Multiple choice biology option c: ecology and conservation hotspots and methods of conservation biodiversity: conservation conservation of biodiversity

Which of the following is absent in polluted water : -

  1. Hydrilla

  2. Water hyacinth

  3. Larva of stone fly

  4. Blue green algae
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Stoneflies are exopterygote insects with aquatic nymphs; long antennae, biting mouthparts and a weak flight. Adults have the tendency to feed on lichens and unicellular algae. These are good pollution indicators. Stonefly (Plecoptera order) larva requires well-aerated, non-polluted water. It is absent in polluted water.

So, the correct answer is 'Larva of stonefly'.
Multiple choice biology option c: ecology and conservation hotspots and methods of conservation biodiversity: conservation conservation of biodiversity

Which of the following is not found in polluted water?

  1. Blue green algae

  2. Larvae of stone fly

  3. Water hyacinth

  4. Sewage fungi
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Stoneflies are found in clean and cool flowing streams. They spend most part of their life in the larval form and are sensitive to water pollution. In particular, stoneflies are sensitive to changes in dissolved oxygen and water temperature. They need a high amount of dissolved oxygen to live comfortably. When the dissolved oxygen falls or the temperatures rise and stoneflies disappear. The presence of stoneflies is a reliable indicator of excellent water quality
So, the correct answer is 'Larvae of stone fly'
Multiple choice biology option c: ecology and conservation hotspots and methods of conservation biodiversity: conservation conservation of biodiversity

Which among the following in excess quantity indicates the contamination of Ganga water bodies?

  1. Dissolved minerals

  2. Coliform bacteria

  3. Dissolved carbon

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

A lot of pathogens are present in water bodies that are contaminated. One of these pathogens is coliform bacteria. This bacteria, like other pathogens, is an indicator of contamination in water bodies. This is because it has a similar reaction to purification and water treatment like other pathogens.

So, it can be used as an indicator of water contamination. So, option B is the correct answer.

Multiple choice biology ecosystem : structure and function biogeochemical cycles - sedimentary biogeochemical cycle nitrogen and phosphorus cycles

Which one of the following pairs is not correctly matched?

  1. Production of sulphur dioxide - Burning of coal

  2. Depletion of ozone layer - Release of chlorofluorocarbons in the atmosphere

  3. Eutrophication - Increase in nitrogen and phosphorus contents in aquatic bodies

  4. Dec:ease in B.O.D. of pond water - Increase in global temperature
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice geography pollution - types and sources study of water pollution threats to water resource major hazards in india and prevention pollution and environment

One of the measures of water pollution is the quantity of dissolved ________.

  1. Nitrogen

  2. Chlorine

  3. Oxygen

  4. Carbon dioxide
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

  • Dissolved oxygen is the amount of free oxygen present in water which is not bound to any other element.
  • If there is an increase in pollution rates dissolved oxygen rate drops drastically affecting aquatic life.

Multiple choice geography pollution - types and sources study of water pollution threats to water resource major hazards in india and prevention pollution and environment

The process of depletion of oxygen from water bodies occurring either naturally or due to human activity is known as ____________.

  1. Eutrophication

  2. Biomagnification

  3. Both a and b

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Eutrophication is the enrichment of water bodies with nutrients, leading to excessive plant growth and subsequent oxygen depletion as the plants decay.

Multiple choice geography pollution - types and sources study of water pollution threats to water resource major hazards in india and prevention pollution and environment

Alteration in physical, chemical or biological characteristic of water, making it unsuitable for designated use in its natural state, is ________.

  1. Water pollution

  2. Soil pollution

  3. Air pollution

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Water pollution can be defined as alteration in physical, chemical or biological characteristics of water, making it unsuitable for designated best use in its natural state.  

World Health Organization (WHO) has defined water pollution as inclusion of any foreign material either from natural or other sources into a water body, thereby changing the natural qualities of water and making it unusable for its intended purpose.

Multiple choice geography pollution - types and sources study of water pollution threats to water resource major hazards in india and prevention pollution and environment

The phenomenon of concentrated toxic deposition at the higher trophic level is known as _________.

  1. Biomagnification

  2. Bioaccumulation

  3. Eutrophication

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Biomagnification refers to the increase in concentration of a substance, such as a toxic chemical, as it moves up the trophic levels of a food chain.

Multiple choice geography pollution - types and sources study of water pollution threats to water resource major hazards in india and prevention pollution and environment

__________ in the water is essential for protection against dental caries and weakening of the bones, but higher levels can have an adverse effect on health.

  1. Chlorides

  2. Fluorides

  3. Cyanide

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

Fluoride in drinking water at low concentrations helps prevent tooth decay, but excessive levels can lead to fluorosis, which affects bones and teeth.