Which of the following must happen first if natural selection is going to take place? 1. variation in organisms 2. selective advantage of one trait over another 3. reproduction 4. time 5. generic mutation

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

a- all cells come from pre-existing cells