Answer:
Revolution of earth around the sun
Explanation:
There are two events,
A: the selection belongs to the specific species, or
A' : the selection does not belong to the specific species.
Receptor proteins, they then send out the signal to perform a task or duty
Nitrogen fixation would not occur and that would mean that there would be a lack of nitrogen and it wouldn't be able to sustain life. Since nitrogen is an essential element in every amino acid, that also means in every protein. It essential to life and without it life would mostly likely not exist.<span />