The term extinction applies to the eradication of an entire what ? ?

Extinction refers to the eradication of an entire Species. Hope this helped!

b. the carbon cycle ensures living things have a source of hydrogen

the corpus luteum secretes estrogens and progesterone. the latter hormone causes changes in the uterus that make it more suitable for implantation of the fertilized ovum and the nourishment of the embryo. if the egg is not fertilized, the corpus luteum becomes inactive after 10–14 days, and menstruation occurs.

i hope this : )