Question 1

Which of the following best describes the process of spermatogenesis in humans?

Accepted Answer

It involves two meiotic divisions resulting in four haploid spermatids from each primary spermatocyte.

Question 2

Why are the testes located outside the body cavity in the scrotum?

Accepted Answer

To maintain a temperature slightly below body temperature, which is optimal for spermatogenesis.

Question 3

Which hormone directly stimulates Leydig cells to produce testosterone?

Accepted Answer

Luteinizing hormone (LH)

Question 4

What is the role of Sertoli cells in the seminiferous tubules?

Accepted Answer

They protect germ cells from toxins and produce inhibin.

Question 5

During oogenesis, why are the resulting cells of the first meiotic division unequal in size?

Accepted Answer

To provide one large secondary oocyte with most of the cytoplasm and a small polar body.

Question 6

Which event triggers the completion of the second meiotic division in the secondary oocyte?

Accepted Answer

Fertilization by a sperm cell

Question 7

What is the main function of the corpus luteum after ovulation?

Accepted Answer

To secrete estrogen and progesterone for about two weeks

Question 8

Which hormone is responsible for the positive feedback that triggers the LH surge and ovulation?

Accepted Answer

Estrogen

Question 9

If fertilization does not occur, what hormonal changes lead to menstruation?

Accepted Answer

Decreased levels of estrogen and progesterone due to degeneration of the corpus luteum

Question 10

Which of the following best explains the mechanism of action of RU-486 (mifepristone)?

Accepted Answer

It blocks progesterone receptors, preventing progesterone from maintaining the endometrium.

Question 11

What is the primary function of the acrosome in a sperm cell?

Accepted Answer

To contain enzymes that help penetrate the egg's protective layers

Question 12

Which process prevents polyspermy during fertilization in sea urchins?

Accepted Answer

Formation of a fertilization envelope after the cortical reaction

Question 13

In mammals, where does fertilization typically occur?

Accepted Answer

In the oviduct (Fallopian tube)

Question 14

Which hormone is detected by most over-the-counter pregnancy tests?

Accepted Answer

Human chorionic gonadotropin (hCG)

Question 15

What is the effect of high levels of estrogen on the anterior pituitary around day 12 of the ovarian cycle?

Accepted Answer

It stimulates a surge in LH (and some FSH), triggering ovulation.

Question 16

Which of the following is a correct sequence of events in the female reproductive cycle?

Accepted Answer

Follicle maturation → Ovulation → Corpus luteum formation → Menstruation

Question 17

Which of the following best explains why only one follicle typically completes maturation and ovulation each cycle?

Accepted Answer

The dominant follicle outcompetes others for FSH and nutrients, causing the rest to degenerate.

Question 18

Which of the following equations correctly represents the chromosome number change during spermatogenesis?

Accepted Answer

$$2n \xrightarrow{Meiosis\ I} n \xrightarrow{Meiosis\ II} n$$

Question 19

Which of the following is a real-world application of pheromones in humans, as suggested by some studies?

Accepted Answer

Synchronization of menstrual cycles among women living together

Question 20

What is the main reason why only one sperm is allowed to fertilize an egg?

Accepted Answer

To prevent abnormal chromosome numbers in the zygote

Gametogenesis and Fertilization: Spermatogenesis, Oogenesis, and Hormonal Regulation

Study Guide - Practice Questions