Answer:
The primary species something regenerates off of.
For example: Let's say there was an animal called a goblegg.
If the animal who gives it the main components is an chicken, the primary species is a chicken.
Hope this helps!
Definitely i would expect them to concern themselves with your problems when they are so beset with their own. Beset means having a lot of trouble with something, or having to deal with a lot of something causes problems. For example in a sentence; With the amount of traffic nowadays, even a trip across town is beset with dangers.
CO2molecule is a reactant in the first step and a final product in the fourth step of the Calvin-benson