The control and experimental groups are not designed to be identical, since on one hand the experimental group gets a treatment (a medicine or something else). On the other hand, the control group does not get this treatment (or gets a 'fake' treatment). This way researchers can find differences between both groups and therefore can decide whether the treatment works or not.
<span>The correct answer is the chromatin. The chromosomes of all organisms, excluding bacteria, are made of chromatin. Chromatin is a group of macromolecules consisting of RNA, DNA, and protein.</span>
