Welcome to the Quiz!
This quiz contains 10 questions from a mix of 1 subtopics.
Which of the following is NOT a reason why bony fish have evolved specialised respiratory systems?
bony fish have scaly skin that enhances gas exchange
water is denser and more viscous than air, resulting in slower diffusion
water has less oxygen than air
bony fish are very active so have high oxygen demands
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What structure directly covers the gills of bony fish?
scales
lamellae
filaments
operculum flap
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Which of the following is NOT an adaptation of gills for efficient gas exchange?
rich blood supply
thin layers of gills
large surface area
parallel flow of blood and water
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What does the countercurrent flow of blood and water in gills mean?
blood and water flow in the same direction
blood and water flow at different speeds
blood and water flow in opposite directions
blood and water do not flow
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Which of the following is true about the countercurrent exchange principle in fish gills?
it allows oxygen-rich blood to meet water that has had most of its oxygen removed
it reduces the diffusion of oxygen into the blood
it maintains a steep concentration gradient across the entire gill
it enables less efficient gas transfer than parallel flow
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What happens when a fish opens its mouth?
it increases the volume of the buccal cavity and increases the pressure
it does not change the volume of the buccal cavity or the pressure
it decreases the volume of the buccal cavity and increases the pressure
it increases the volume of the buccal cavity and decreases the pressure
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Which of the following is an adaptation of gills for efficient gas exchange?
overlapping filament tips decrease resistance, slowing water flow over gills
overlapping filament tips increase resistance, speeding up water flow over gills
overlapping filament tips increase resistance, slowing water flow over gills
overlapping filament tips decrease resistance, speeding up water flow over gills
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What does the decrease in pressure in the buccal cavity cause when a fish opens its mouth?
it has no effect on water movement
it pushes water out of the buccal cavity
it pulls water into the buccal cavity
it causes water to flow out through the operculum
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What does the unidirectional water flow driven by the buccal cavity provide?
freshly oxygenated water and removal of carbon dioxide
stagnant water and accumulation of carbon dioxide
stagnant water and removal of carbon dioxide
freshly oxygenated water and accumulation of carbon dioxide
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Explain how the countercurrent exchange system in fish gills enables efficient gas transfer.
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