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 increase efficiency of gas exchange.
C)The only effect would be the fish's discomfort from this treatment.

Question

Quizplus · Accepted Answer

This backward movement would reduce the efficiency of gas exchange because fish gills are adapted to extract oxygen from water flowing in a specific direction (front to back). Reversing this flow disrupts the counter-current exchange mechanism, reducing oxygen uptake.

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