Environmental Studies · General Awareness

Water Quality and Pollution

1,303 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 business organisation and correspondence industrial pollution and degradation of environment sources of pollution environmental conservation environment and conservation

Any unfavorable alteration of the environment may be called as

  1. eutrophication

  2. environmental pollution

  3. biomagnigication

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

Environmental pollution is defined as the introduction of harmful materials or unfavorable alterations into the environment that cause adverse effects on living organisms.

Multiple choice our life and environment geography

Eutrophication is a _____.

  1. Neutral sign for ecosystem

  2. Dual-sided sign for ecosystem

  3. Bad sign for ecosystem

  4. Good sign for ecosystem
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Eutrophication can have serious effects, like algal blooms that block light from getting into the water and harm the plants and animals that need it. If there's enough overgrowth of algae, it can prevent oxygen from getting into the water, making it hypoxic and creating a dead zone where no organisms can survive.

Multiple choice zoology our environment - our concern biomagnification the effects of human activities on ecosystems bioaccumulation and biomagnification

Increase in concentration of a toxicant at successive trophic levels is called _________.

  1. Algal bloom

  2. Biomagnification

  3. Eutrophication

  4. Accelerated eutrophication

  5. Decelerated eutrophication
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

  • Algal bloom: It is the rapid growth of algae in water due to which coloured scums are formed on the surface.
  • Biomagnification: When a toxic substance gets incorporated in the food chain, its concentration gets increased at each successive trophic level. This is called biomagnification.
  • Eutrophication: It is the phenomenon of nutrient enrichment of nitrogen and phosphorus in a water body that supports a dense growth of plants and animal life. Due to nutrient enrichment, excess growth of algae occurs which is called algal bloom. When these algae die, their organic matter gets decomposed and this results in the depletion of oxygen leading to death of aquatic animals. This process is called eutrophication. 
So, the correct answer is 'Biomagnification'.

Multiple choice zoology our environment - our concern biomagnification the effects of human activities on ecosystems bioaccumulation and biomagnification

In a lake polluted with pesticides, which one of the following will contain the maximum amount of pesticide.

  1. Small fish

  2. Microscopic animals

  3. Big fish

  4. Birds feeding on water organisms
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

If a lake is polluted with pesticides, large fish will contain the maximum amount of pesticide. The process due to which large fish will contain the maximum amount of pesticide is called biological magnification. It is also called as biomagnification. Phytoplanktons and zooplanktons absorb pesticide from the polluted water. Small fishes eats phytoplankton and zooplanktons. There will be increased accumulation of pesticide in their bodies. These small fishes are eaten by big fish. Hence, the big fish will have the maximum amount of pesticide.

Thus, the correct answer is 'Big fish.'

Multiple choice zoology our environment - our concern biomagnification the effects of human activities on ecosystems bioaccumulation and biomagnification

When the rate of the consumption of organic matter of the effluent by floes increases, then the BOD of the effluent.

  1. Significantly increases

  2. Significantly reduces

  3. No change in BOD

  4. Oxygen is not required for this process
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

  • Biochemical oxygen demand (BOD) is a measure of how much organic pollution is in water. The BOD test measures the amount of dissolved oxygen in water that is used up due to the breakdown of organic pollutants, such as sewage, in a certain number of days. 
  • Increased BOD means that a lot of oxygen is being used up, typically by bacteria breaking down organic material. 
So, the correct option is 'Significantly increases'.

Multiple choice zoology our environment - our concern biomagnification the effects of human activities on ecosystems bioaccumulation and biomagnification

The phenomenon of accumulation of heavy metal and pesticide in trophic level is called as

  1. Eutrophication

  2. Biomagnification

  3. Composting

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

Biomagnification is defined as the process by which a compound (such as a pollutant or pesticide) increases its concentration in the tissues of organisms as it moves up the trophic levels

So, the correct answer is 'Biomagnification'

Multiple choice zoology our environment - our concern biomagnification the effects of human activities on ecosystems bioaccumulation and biomagnification

Which of the following is associated with biological amplification? 

  1. SO$ _4$

  2. DDT

  3. Sewage

  4. All of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The different trophic level of an ecosystem interacts with each other and they are interdependent on each other. Biological magnification is a process where pollutants such as pesticides or heavy metals move up the food chain, passes into rivers or lakes and consumed by aquatic organisms such as fish, which in turn are eaten by large birds, animals or humans. It occurs when the concentration of a substance, such as DDT or mercury, in an organism, exceeds the background concentration of the substance in its diet. 

Thus, the correct answer is option B.

Multiple choice zoology our environment - our concern biomagnification the effects of human activities on ecosystems bioaccumulation and biomagnification

Increasing concentration of accumulated pollutant along food chain is

  1. Biomagnification

  2. Bioaccumulation

  3. Eutrophication

  4. Nutrient cycling
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A few toxic substances, often present in industrial wastewaters, can undergo biological magnification (biomagnification) in the aquatic food chain. Biomagnification refers to an increase in the concentration of the toxicant at successive trophic levels. This happens because a toxic substance accumulated by an organism cannot be metabolised or excreted, and is thus passed on to the next higher trophic level in a food chain.

Multiple choice zoology our environment - our concern biomagnification the effects of human activities on ecosystems bioaccumulation and biomagnification

Increase in the concentration of the toxicant at successive trophic levels is known as

  1. Biomagnification

  2. Biodeterioration

  3. Biotransformation

  4. Biogeochemical cycling
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Biomagnification, also known as bio-amplification or biological magnification, is the increasing concentration of a substance, such as a toxic chemical, in the tissues of tolerant organisms at successively higher levels in a food chain. The substances become increasingly concentrated in tissues or internal organs as they move up the chain. Bioaccumulants are substances that increase in concentration in living organisms as they take in contaminated air, water, or food because the substances are very slowly metabolized or excreted.

So the correct answer is 'Biomagnification'.

Multiple choice zoology our environment - our concern biomagnification the effects of human activities on ecosystems bioaccumulation and biomagnification

If a water body is contaminated with toxicant, its biomagnification will be more marked in

  1. Plankton

  2. Small fish

  3. Birds

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

 It is seen that the level of toxicant increases as the food chain progresses. It means, the primary consumers will have more toxicant concentration than the producers, the secondary consumers will have more than primary consumers and so on. The highest concentrations will be seen in the top carnivore. This is because the consumers at the successive trophic level consume more than the previous level to fulfil the energy requirements. Due to this, toxicant keeps on accumulating in the successive trophic levels in higher concentrations. This process is called the biomagnification. So, planktons will have least and birds will have the most toxicant presence.

Hence, the correct answer is 'Birds'.

Multiple choice zoology our environment - our concern biomagnification the effects of human activities on ecosystems bioaccumulation and biomagnification

Biomagnification refers to an increase in the concentration of the toxicant at successive trophic levels. This happens because

  1. A toxic substance accumulated by an organism cannot be metabolised

  2. A toxic substance accumulated by an organism cannot be excreted

  3. A toxic substance passed on to the next highest trophic level

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Biomagnification, also known as bioamplification or biological magnification, is the increasing concentration of a substance, such as a toxic chemical, in the tissues of tolerant organisms at successively higher levels in a food chain. Biomagnification process occurs when certain toxic chemicals and pollutants such as heavy metals, pesticides or polychlorinated biphenyls (PCBs) compounds go up the food chain by working their way through the environment and into the soil or the water systems after which they are eaten by aquatic animals or plants. Biomagnification occurs in the higher trophic levels of the food chain/web , where exposure to chemicals takes place mostly through food consumption rather than water uptake. Spraying a marsh to control mosquitoes will cause trace amounts of DDT to accumulate in the cells of microscopic aquatic organisms causing accumulation which cannot be metabolized.

So the correct option is 'all of the above'

Multiple choice evs let's clean together cleanliness who will do this work? personal and public cleanliness

Contamination of water with sewage is indicated by cysts of

  1. Escherichia

  2. Entamoeba

  3. Pseudomonas

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

Several outbreaks worldwide caused by the presence of E. histolytica have been reported associated with sewage contamination.

Entamoeba histolytica is an invasive, pathogenic protozoan, causing amoebiasis, and an important cause of diarrhoea in developing countries. The life cycle of the parasite is represented by two forms: the cyst and the trophozoite. The cyst is the infective and non-motile form of the parasite.  It is excreted in the faeces and can survive for weeks in the environment.
The organism can be prevalent in cold regions as well as tropical and subtropical regions that have contaminated water. In fact, E. histolytica is an important cause of morbidity and/or mortality wherever sewage facilities are inadequate. As is the case for other intestinal protozoan pathogens, wastewater treatment techniques are reported not to be very efficient for E. histolytica elimination possibly because of their resistance to disinfectants and the small size of the cysts. 
So the answer is 'Entamoeba'. 

Multiple choice evs more about organ system introduction to excretory system structures and functions related to the excretory system introduction to excretion

Many freshwater animals cannot live for long in sea water and nice versa mainly because of the

  1. Change in N levels

  2. Change in the levels of thermal tolerance

  3. Variations in light intensity

  4. Osmotic problems

  5. Spectral quality of solar radiation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Freshwater and marine organisms are adapted to specific osmotic environments. Moving them between these environments causes osmotic stress, leading to cell swelling or dehydration, which is fatal.

Multiple choice biology wastewater story basics of water pollution sewage treatment wastewater treatment - need and methods personal and public cleanliness who will do this? water borne disease hygiene - a key to healthy life

Study the given differences between primary sludge and activated sludge and select the incorrect ones. 

Primary Sludge Activated sludge
(i) It is sludge formed during primary sewage treatment. It is sludge formed during secondary sewage treatment.
(ii) It possesses flocs of decomposer microbes.  It does not possess flocs of decomposer microbes.
(iii) It does not require aeration.  Formation of activated sludge requires aeration.
(iv) A lot of decomposition occurs during formation of primary sludge.  Very little decomposition occurs during formation of activated sludge. 

  1. (i) and (ii)

  2. (ii) and (iv)

  3. only (iv)

  4. (ii) and (iii)
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The primar sludge is formed during primary sewage treatment, while activated sludge is a sludge during secondary sewage treatment, little decomposition occurs during primary sludge formation, while lot of decomposition occurs during activated sludge.

So, the correct option is 'only (iv)'.

Multiple choice biology wastewater story basics of water pollution sewage treatment wastewater treatment - need and methods personal and public cleanliness who will do this? water borne disease hygiene - a key to healthy life

Which of the following is correct for sewage discharge in river?

  1. At the discharge point B.O.D is high and fishes die

  2. At the discharge point D.O. is high

  3. B.O.D increase downstream ion river

  4. From the discharge 50 KM away, Fishes ,die
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When sewage is discharged into a river, the high organic load increases the biological oxygen demand (BOD) as microorganisms decompose the waste, leading to a drop in dissolved oxygen (DO) and the death of aquatic organisms like fish.