Causes and Effects of Water Pollution

Q.

What are coliform bacteria?

Q. Which of the following can be the reason(s) for increase in BOD in water bodies?

1. When fertilizers enter into water, it helps algae to bloom.
2. When fertilizers enter into water, it starts to react with dissolved oxygen.
3. When algae die, large organic matter gets released.
4. When bacteria starts decomposing the dead organic matter.

Q. How does an aerobic bacteria contribute to contamination of water?

1. It enables the aquatic life to survive.
2. It releases a large number of harmful chemicals.
3. It consumes all available oxygen in water.
4. It decreases the water temperature.

Q.

List at least three things that help us detect that food is unfit for consumption?

Q. Which of the following are the diseases caused due to intake of polluted water?

1. Cholera
2. Typhoid
3. Asthma
4. Hepatitis-A

Q. What are water-borne diseases? Name few water-borne diseases. [3 marks]

Q. Excess of _________ in water causes fluorosis.

1. arsenic
2. lead
3. fluorine
4. mercury

Q. One of the free-living, anaerobic nitrogen-fixer is

1. Azotobacter
2. Beijerinckia
3. Rhodospirillum
4. Rhizobium

Q. Plant nutrients affect aquatic life. Sort the steps involved accordingly.

1. Excess nutrients enter the water bodies.
2. Excess nutrients help algae to bloom.
3. Algae spreads and die off.
4. Decomposition of dead organic matter.
5. Dissolved oxygen decreases.

Q.

Runoff of fertilizers into lakes leads to

1. Drying of the lakes

2. An increased production of fish due to a lot of nutrients

3. Death of fish due to lack of oxygen

4. Oxides of nitrogen in water

Q.

Ashes after cremation of dead bodies are immersed into river bodies. This causes __________ pollution.

1. Air

2. Water

3. Soil

4. Noise

Q. Which of the following badly affects the aquatic life the most?

1. Acid Rain
2. Deforestation
3. Eutrophication
4. Chloroflourocarbons

Q.

Oxygen consuming bacteria are commonly known as

Q. What does the presence of a green layer over a water body in the image depict?

1. Biomagnification
2. Silting
3. Bioaccumulation
4. Eutrophication

Q.

How hepatitis is caused?

Q. Waterborne diseases are caused due to contaminated air droplets.

1. False
2. True​

Q.

Assertion: Eutrophication shows an increase in productivity in water.
Reason: With increasing eutrophication, the diversity of the phytoplankton increases.

1. If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.

2. If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.

3. If Assertion is correct but Reason is incorrect.

4. If Assertion is incorrect but Reason is correct.

Q. The foot and mouth disease is caused by a __________

Q. What happens in water bodies when the water temperature increases?

1. Aquatic life diversity increases in the water.
2. Aquatic life diversity reduces in the water.
3. Amount of dissolved oxygen decreases.
4. Amount of dissolved oxygen increases.

Q. Hot water discharged by the industries into water bodies does not affect the aquatic animals.

1. True
2. False

Q. Runoff of fertilizers into lakes leads to:

1. Drying of the lakes.
2. An increased production of fish due to a lot of nutrients.
3. Death of fish due to lack of oxygen.
4. Oxides of nitrogen in water.

Q.

__________is caused due to accidental discharge of petroleum products into the water bodies.

1. Industrial pollution

2. Thermal pollution

3. Oil spill

4. Soil pollution

Q. Which of the following has a high nutrient content but can cause side effect?

1. Manure
2. Biofertilizer
3. Fertilizer
4. All of the above