The answer would be: Endometrium.
<span>D. is fully functional and able to produce and release active sperm after puberty
</span>Unlike the female reproductive system, the male reproductive system
is fully functional and able to produce and release active sperm after puberty
NOT:
A. is affected by hormones.
B. utilizes a menstrual cycle, which is nearly 28 days long.
<span>C. produces eggs.</span>
Internal means its on the inside
external means its on the outside
so an internal regulator is when the proteins respond to events on the inside of a cell
and an external regulator is when the proteins respond to events outside the cell
Use of transgenic animals to improve human health and animal production. ... The advance in the generation of pigs to be used as the source of organs for patients and in the preparation of pharmaceutical proteins from milk and other possible biological fluids from transgenic animals is described.