Light skin pigmentation enables the weak ultraviolet radiation of northern latitudes to penetrate the skin  and stimulate the formation of _________, which is necessary for calcium regulation. 

How do pygmy chimpanzees (bonobos) primarily differ from common chimpanzees? 

The most solitary ape, the only one who does not live in a pair-bonded group or larger multi-male/female group is the 

The ________ is the site of sperm production.

In males, FSH stimulates ________ cells to produce ________.

Male emission is innervated by the ________ nervous system.

Aldosterone is classified as a(n) ________ and binds to ________ receptors.

The ovary ________.

The ________ produce(s) a secretion that contains fibrinolysin (an enzyme to liquefy semen clots) and seminalplasmin (an antibiotic).

The ________ surround(s) the male urethra and secrete(s) a thick, clear, alkaline mucus known as pre-ejaculate.