Answer:
Aristotle first wrote about the practice of animal testing in ancient
Greece during the third century BC.
Explanation:
In facilitated diffusion, substances move into or out of cells down their concentration gradient through protein channels in the cell membrane. Simple diffusion and facilitated diffusion are similar in that both involve movement down the concentration gradient.
<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>
