What has a fixed arrangement of atoms

explanation:

on disadvantage of hydroelectric power is the cost. another disadvantage of using hydroelectric power is finding a water source powerful enough to harvest hydroelectric power.

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

meiosis is the first to occur after the nuclei of opposite of opposite mating types fuse

1. is geographic distribution

2 is increasing complexity

3 is transitional forms