In the gill of a fish, water and blood circulate , which transfer efficiency.
A) in the same direction; increases
B) in opposite directions; increases
C) in the same direction; decreases
D) in opposite directions; decreases

Question

Quizplus · Accepted Answer

In fish gills, water and blood circulate in opposite directions, a mechanism known as countercurrent exchange, which maximizes the efficiency of oxygen transfer from water to blood.

In the Gill of a Fish, Water and Blood Circulate