11. A. Ovulation.
12. Semen.
13.The fluid--to some degree--helps protect the sperm from the acidic environment of a woman's vagina, which could otherwise damage and kill said sperm.
14. During the menstrual cycle, the endometrium grows to a thick, blood vessel-rich tissue lining, representing an optimal environment for the implantation of a blastocyst upon its arrival in the uterus; the body also begins to prepare for ovulation again.
15. Both the testes and the ovaries produces entities needed for the process of reproduction. But while the ovaries create eggs, the testes create sperms.
16. On the 7th day; on the 21th day.
17. C. The amniotic sac.
18. The umbilical cord.
19. The germinal stage, the embryonic stage, and the fetal stage.
20. two eggs; a single egg.
21. Since the pituitary gland produces hormones that stimulating all the other hormone-producing glands to produce their own hormones, that tumor could potentially causes the body to function incorrectly: For example, the body could not produces the required hormones needed for the body to start producing sperms/eggs, preventing the person's ability to reproduce overall.
