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WorksheetsEutrophication
Total questions: 16
Worksheet time: 16mins
What is the original cause of eutrophication?
Too many predators
Too many herbivores
Excess fertilizer
Too much oxygen
Which describes a dead zone?
An area of low oxygen in water
A single point where water drains to
Where fresh water and salt water meet
One of the primary human causes of dead zone formation is:
Burning of fossil fuels
Deforestation
Overfishing
Farming with fertilizers
How does eutrophication cause the death of aquatic organisms
the build up of carbon dioxide in the water
the lack of nitrogen in the water
the lack of carbon dioxide in the water
the lack of oxygen in the water
In eutrophication, dissolved oxygen levels decrease because
bacteria use it as they decompose organic material
algae uses it during photosynthesis
it reacts with hydrogen to form H2O (water)
fish use it up as they consume algae
What is the very next thing that happens after fertilisers enter a river in eutrophication?
Fish die due to a lack of oxygen
Plants below the surface die due to a lack of sunlight
The number of aerobic bacteria increases
Fast growth of plants
In eutrophication, what does 'algal bloom' refer to?
The rapid increase in the number of bacteria
The rapid increase in the number of plants
The rapid decrease in the number of fish
The rapid increase in the amount of nitrates in the river
When algae levels increase in a body of water, it
cuts off light to plants at the bottom.
increases light to the plants on the bottom.
causes dissolved Oxygen levels increase.
causes bacteria populations decrease.
Which nutrients are primarily responsible for eutrophication?
Phosphorus and nitrogen
Carbon and oxygen
Hydrogen and helium
Sulfur and potassium
Hypoxia is a state of depleted oxygen in water.
True
False
What are the consequences of hypoxia for aquatic life?
The green plants on the surface of the lake turned out the be algae! There is a sudden increase in the rate of growth of the algae. What would happen next?
The algae continue to grow due to excess nutrients, and some of the algae die
The algae would stop growing
The algae are not affected by the fertilisers
In a dead zone, _________ levels are really low such that living organisms are not able survive.
nitrogen
oxygen
fertilizer
carbon dioxide
Bacteria does not use up a lot of oxygen
TRUE
FALSE
Eutrophication can happen in a river or lake
TRUE
FALSE
An increase in the amount of nutrients in a lake is known as
calcification
cellular respiration
eutrophication
photosynthesis
