Answer:
C: Hormones
Explanation:
hormones do not "signal" other cells. I hope this helps :)
Answer:
vancomycin
Explanation:
β-lactam antibiotics are those antibiotic that that contain a beta-lactam ring (the cyclic amide with the nitrogen atom attached to the β-carbon) in their molecular structures. This class of antibiotics is the most commonly used and it includes penicillin derivatives, cephalosporins, monobactams, and carbapenems. The mechanism of action of β-lactam antibiotics is inhibition of cell wall biosynthesis in the bacteria.
I would say immigration only.
emigration would theoretically reduce the genetic variation as unique individuals leave, but immigration would bring unique traits into circulation in an ecosystem.
I'm not super great at biogy tho so this might not be right... :)