Testosterone is produced by the

324. Testosterone is produced by the
The correct answer is D. Leydig cells.
Leydig cells, located in the interstitial tissue of the testes, are responsible for producing testosterone.

325. The majority of the semen is produced by the
The correct answer is A. seminal vesicles.
Seminal vesicles contribute approximately 60-70% of the total volume of semen, providing fructose for sperm energy and other substances.

326. The follicular phase of the menstrual cycle is also known as the proliferative phase of the endometrium.
The correct answer is A. proliferative.
During the follicular phase, estrogen levels rise, causing the endometrium to thicken and proliferate in preparation for a potential pregnancy.

327. Reproduction in birds compares to reproduction in reptiles in that
The correct answer is E. the eggs of both birds and reptiles have protective shells.
Both birds and reptiles lay amniotic eggs, which are characterized by a protective shell and extraembryonic membranes that allow for development on land.

328. In humans, fertilization of an egg normally takes place when the sperm and egg unite in the:
The correct answer is C. fallopian tube.
Fertilization typically occurs in the ampulla region of the fallopian tube (oviduct).

329. The corpus luteum produces progesterone, which inhibits ovulation.
The correct answer is D. Progesterone.
After ovulation, the ruptured follicle transforms into the corpus luteum, which primarily produces progesterone. Progesterone inhibits the release of GnRH, LH, and FSH, thereby preventing further ovulation.

330. Approximately two-thirds of the male ejaculate is produced and secreted by the:
The correct answer is E. seminal vesicles.
As mentioned in question 325, the seminal vesicles contribute the largest portion (about 60-70%, or roughly two-thirds) of the seminal fluid.