definition: This is a species whose presence is critical to the composition and integrity of the community. Example: Predators often control the population of their prey. If wolves are removed from a specific community, the population of moose increases and another predator may take the place of the wolf.

dude i stopped reading after the first 7 words but hey you seem real smart thats awesome have a great day

endo:

regulates body hormones, aldosterone, vasopressin

neural:

signal, regulates body using electric signals, reflex

endo has to do with hormones; aldosterone and vasopressin are both hormones. i also had this question and got it right : d

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).   so the answer is a.