Water flowing back and forth across the gills of fish is known as _____.
A) capillary movement
B) counter current exchange
C) deoxygenation
D) pharyngeal movement
E) gill slits

Question

Quizplus · Accepted Answer

Counter current exchange is the process in which water flows in one direction and blood flows in the opposite direction across the gills of fish. This creates a gradient where oxygen diffuses from the water into the blood and carbon dioxide diffuses from the blood into the water. This process enhances the oxygen absorption capabilities of fish gills.

Water Flowing Back and Forth Across the Gills of Fish