(ii) Fish use their gills as a gas exchange surface. Suggest three ways in which fish gills are adapted for efficient gas exchange.
(3)
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3

Exchange of gases in fish is very efficient because of: the large surface area of the gills. the large surface area of the blood capillaries in each gill filament. the short distance required for diffusion – the outer layer of the gill filaments and the capillary walls are just one cell thick.

Proteins on the boood determine a person’s blood type. antibodies( i’m not completely sure, i haven’t done this yet in bio) in the blood attack foreign blood not compatible with the antigens on the blood