Which era is characterized by stromatolites as the most abundant fossil? Mesozoic
Precambrian
Paleozoic
Cenozoic

Precambrian

Explanation:

tromatolites were common in Precambrian time. Some of the first forms of life on Earth are recorded in stromatolites present in rocks 3.5 billion years old.

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