Countercurrent exchange in the fish gill helps to maximize
A) endocytosis.
B) blood pressure.
C) diffusion.
D) active transport.
E) osmosis.

Question

Quizplus · Accepted Answer

Countercurrent exchange in the fish gill provides a gradient that maximizes the diffusion of oxygen into the bloodstream and carbon dioxide out of the bloodstream. This is a very effective method of gas exchange, ensuring that the fish receives as much oxygen as possible from the water passing over its gills.

Countercurrent Exchange in the Fish Gill Helps to Maximize