The answer is A. the substrate serves as a key to activate the enzyme.
Answer: Plants,Bacteria, and protists
Explanation:
I think the correct answer from the choices listed above is option A. When crossing-over takes place, chromosomes exchange corresponding segments of DNA. Corresponding genes on non-sister chromatids are exchanged at chiasmata. Hope this answers the question.
So we all know that the Earth rotates around the Solar system all the time nonstop. But wait there is more. One half of the Earth which is North America and South America are faced to the sun so you can tell that we are in summer. While we are in summer,the other half of the Earth which is Europe,Africa,Asia and Austrialia ( I think I spelled that wrong who cares about that) they are in winter. This process continues nonstop there is no break.