During the day in Lake Constance, the zooplankton D. hyaline departs for the depths where food is scarce and the water cold. D. galeata remains near the warm surface where food is abundant. Even though D. galeata grows and reproduces much faster, its population is often outnumbered by D. hyaline.

Inferences:
There are two sub species of Zooplankton, one is D.hyaline and other one is D.galeata.
D. Galeata produces faster but still the population of THE.hyaline is more than D. Galeata.
D.hydaline stays at the depth and D.Galeate stays at the surface of the lake.

Which of the following, if true, most helps to resolve the apparent paradox?


A. The number of species of zooplankton living at the bottom of the lake is twice that of species living at the surface.
Wrong. This is very confusing but notice it’s not telling us which species of zooplankton is living in the bottom or at the surface.

B. Predators of zooplankton, such as whitefish and perch, live and feed near the surface of the lake during the day.
Right. If they are being killed more, it’s natural that D.hyaline will outnumber D.Galeata.

C. In order to make the most of scarce food resources, D.hyaline matures more slowly than D. galeata.
Wrong. This wouldn’t resolve the paradox but give the paradox it’s required strength.

D. D. galeata clusters under vegetation during the hottest part of the day to avoid the Sun’s rays.
Wrong. Out of context.

E. D. galeata produces twice as many offspring per individual in any given period of time as does D. hyaline.
Wrong. This is again strengthening the paradox and not resolving it.

they hunt only at day when Hyaline is also at the surface
A should be the answer

B is wrong because the predator hunt ant day time when D.hyaline and D.Galeata both at the surface
A is the right answer because it is telling you that D.hyaline live at the bottom during the night

"During the day in Lake Constance, Zooplankton D. hyaline departs for the depths," meaning it leaves the warm water at the surface to go to the deeper water.

Also, having more species of plankton living at the bottom of the lake wouldn't have an affect the amount of D. galeata on the surface. Only predation can account for this discrepancy making B the correct answer.

If there are any rebuttals, please let me know.

aha thank you