Exchange (AQA A-Level Biology): Quizzes
📚Quizzes
Practise the questions
10 questions from this quiz
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Practise the questions
10 questions from this quiz
Why can't fish exchange gases through their body surface?
Why can't fish exchange gases through their body surface?
They have a waterproof outer covering
How are gill filaments arranged in fish gills?
How are gill filaments arranged in fish gills?
In a stack formation like book pages
What is the main function of gill lamellae?
What is the main function of gill lamellae?
Dramatically increase surface area
What is countercurrent flow in fish gills?
What is countercurrent flow in fish gills?
Water & blood flow in opposite directions
What percentage of available oxygen do fish extract using countercurrent flow?
What percentage of available oxygen do fish extract using countercurrent flow?
Approximately 80%
How much oxygen would be extracted with parallel flow instead?
How much oxygen would be extracted with parallel flow instead?
50%
Why is countercurrent flow more efficient than parallel flow?
Why is countercurrent flow more efficient than parallel flow?
Maintains diffusion gradient fully
What happens when equilibrium is reached in parallel flow?
What happens when equilibrium is reached in parallel flow?
No further diffusion can occur
Where are fish gills located?
Where are fish gills located?
Inside body cavity behind the head
Why must water and blood flow continuously over gills?
Why must water and blood flow continuously over gills?
To maintain diffusion gradients