In an experiment, a fish that had been kept in a tank containing water at 25 $\degree$C was transferred to water at 20 $\degree$C. One hour after the transfer the metabolic rate of the fish was significantly reduced; however, after several days the metabolic rate of the fish had returned to its pre-transfer level. The metabolic changes experienced by the fish in this experiment demonstrate
A) genotypic plasticity.
B) natural selection.
C) acclimatisation.
D) acclimation.
E) compensation.

Question

Quizplus · Accepted Answer

The metabolic changes experienced by the fish, where it initially reduces its metabolic rate upon being transferred to colder water and then adjusts back to its original metabolic rate over several days, is an example of acclimation. Acclimation refers to the physiological adjustment of an organism to changes in its environment, such as temperature, over a short period of time, which is exactly what is described in the scenario.

In an Experiment, a Fish That Had Been Kept in a Tank