Flow of water over fish gills maintains a concentration gradient (of gases)between the blood and the water over the length of the capillary bed; this is referred to as an/a __________ mechanism.

Question

Quizplus · Accepted Answer

The mechanism described is the countercurrent exchange mechanism, where the flow of water over the fish gills is in the opposite direction to the flow of blood in the capillary bed, creating a concentration gradient for efficient gas exchange. This is a passive mechanism as it does not require energy expenditure by the fish. Osmotic mechanisms involve the movement of water across a semi-permeable membrane, and currency exchange is not a relevant term in this context.

Flow of Water Over Fish Gills Maintains a Concentration Gradient