You prop open the gill covers of a fish,tie a string around its tail,and tow it backward through the water.This action forces water to flow in the back of the gill covers,from back to front over the gills,and out through the fish's mouth.What effect would this backward movement have on gas exchange?
A)It would reduce efficiency of gas exchange.
B)It would change from CO₂ out and O₂ in to CO₂ in and O₂ out.
C)There would be no change in the efficiency of gas exchange.

Question

Quizplus · Accepted Answer

Gas exchange in fish relies on a flow of water over the gills in one direction, from front to back. This allows for efficient uptake of oxygen from the water and release of carbon dioxide. Towing the fish backward through the water would disrupt this flow and reduce the efficiency of gas exchange.

You Prop Open the Gill Covers of a Fish,tie a String