Both chemical and mechanical digestion start in the mouth and continue in the stomach.

A. Wolffian refers to structures related to the male reproductive system during embryonic development, not to uterine contractions.

B. Masters Johnson: Masters and Johnson are known for their research in human sexual response, not for describing types of uterine contractions.

C. Graafian: Graafian refers to a mature ovarian follicle, which is unrelated to uterine contractions.

D. Braxton Hicks: Braxton Hicks contractions are irregular, non-labor contractions of the uterus often referred to as "false labor."

A. Sperm; semen: Sperm is the male gamete, and semen is the fluid that contains sperm, but these are not analogous to the ovary, which is a gonad.

B. Testis; semen: The testis is the male gonad that produces sperm, but semen is the fluid that contains sperm. The analogous structure to the ovary is the testis, but this pairing with semen is not correct.

C. Semen; sperm: Semen is the fluid containing sperm, while sperm is the male gamete. Neither is a gonad, so this pairing is not analogous to the ovary.

D. Testis; sperm: The testis is the male gonad that produces sperm, making it analogous to the ovary, which is the female gonad that produces eggs.