In an experiment, the group that is exposed to the variable to be tested is called the

Experimental group

Explanation:

The experimental group is the group that is exposed to the independent variable which is being tested in the experiment. For example, in an experiment to test if the nucleus is required for the survival of amoeba, some of the amoeba cells were enucleated. The enucleated amoeba cells represent the experimental group here.

the cell cycle is the final answer! : )