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Title: AQA AS BIOLOGY GAS EXCHANGE - FISH
Description: Detailed first year (AS) biology notes to aid key revision of topics and enhance knowledge.
Description: Detailed first year (AS) biology notes to aid key revision of topics and enhance knowledge.
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Fish have a waterproof, therefore gas-tight outer covering
...
Structure of the Gills:
Located behind the head
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These are
stacked up in a pile (like book pages)
...
Counter-Current exchange principle:
The flow of blood and water over the gill lamellae is in opposite directions
...
Therefore diffusion of oxygen from the water to the blood takes place
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Diffusion of oxygen from water to blood takes place
...
So about 80% of the oxygen available in the water is absorbed into the blood
of the fish
...
Water is taken through the mouth and forced over gills and out
through an opening on each side of the body
...
Its important to ensure
that maximum gas exchange is achieved, if water and blood flowed
in the same direction, far less gas exchange would occur
Title: AQA AS BIOLOGY GAS EXCHANGE - FISH
Description: Detailed first year (AS) biology notes to aid key revision of topics and enhance knowledge.
Description: Detailed first year (AS) biology notes to aid key revision of topics and enhance knowledge.