quiz 42.5

The sun shining on a tidal pool during a hot day heats the water. As some water evaporates, the pool becomes saltier, causing ___________.

a decreasing in its oxygen content

An oil-water mixture works as an insecticidal spray against mosquitoes and other insects because it ___________.

blocks the openings into the tracheal system

Countercurrent exchange in the fish gill helps to maximize

diffusion

Under identical atmospheric conditions, freshwater _________.

has more oxygen than seawater

Some human infants, especially those born prematurely, suffer serious respiratory failure because of _________.

lung collapse due to inadequate production of surfacant

What would be the consequences if we were to reverse the direction of water flow over the gills of a fish, moving water inward past the operculum, past the gills, then out the mouth? This reversal of water flowing would __________.

reduce efficiency of gas exchange

Countercurrent exchange is evident in the flow of __________.

water across the gills of a fish and the blood within those gills