Achemical reaction is an interaction that always causes what

A chemical interaction is compelled by electrostatic forces which can occur both in vitro (studies are done outside living organisms), and in vivo  (scientists conduct their studies with the use of whole living organisms).  In simpler terms a chemical reaction is a change that occurs when two or more substances combine to form a new substance.

the organisms are not adapted to live in some communities or habitats.

a. suckling by young

b. hypothalamus

c. dopamine

d. trh

e. anterior pituitary

f. mammary glands

g. milk production