Chapter 1 Lectures 1-3

Question 1

Which cell type is located outside the blood-testis barrier?

A. Spermatozoon

B. Secondary spermatocyte

C. Spermatids

D. Primary spermatocyte

E. Spermatogonium

Answer 1

E. Spermatogonium

Question 2

Which of the following cells normally participates in mitotic divisions?

A. Primary oocyte

B. Oogonium

C. Primary spermatocyte

D. Spermatid

E. Secondary spermatocyte

Answer 2

B. Oogonium

Question 3

In a routine chest x-Ray examination, the radiologist sees what appear to be teeth in a mediastinal mass. What is the likely diagnosis, and what is a probable embryological explanation for its appearance?

Answer 3

A mediastinal teratoma which is likely to have arisen from an aberrant primordial germ cell that became lodged in the connective tissue near the heart.

Question 4

When does meiosis begin in the female and in the male?

Answer 4

In the female meiosis begins during embryonic life; in the male, meiosis begins at puberty.

Question 5

At what stages of oogenesis is meiosis arrested in the female?

Answer 5

At prophase (diplotene stage) of the first meiotic division and at metaphase of the second meiotic division.

Question 6

What is the underlying cause of most spontaneous abortion during the early weeks of pregnancy?

Answer 6

Chromosomal abnormalities such as polyploidy or trisomies of individual chromosomes

Question 7

What is the difference between spermatogenesis and spermiogenesis?

Answer 7

Spermatogenesis is the entire process of sperm formation from a spermatogonium. It includes the two meiotic divisions and the period of spermiogenesis.

Spermiogenesis or sperm metamorphosis is the process of transformation of post meiotic spermatids, which looks like an ordinary cell, to highly specialized spermatozoon.

Question 8

The actions of what hormones are responsible for the changes in the endometrium during the menstrual cycle?

Answer 8

Estrogens, secreted by the ovary, support the pre ovulation proliferative phase.

From the time of ovulation, progesterone is secreted in large amounts by the corpus luteum and is responsible for the secretory phase, which prepares the endometrium for implantation of an embryo.

Question 9

Sertoli cells in the testis are stimulated/ by what two major reproductive hormones?

Answer 9

Follicle-stimulating hormone (FSH) produced by the anterior lobe of the pituitary gland and testosterone produced by the Leydig cells of the testis.

Question 10

During spermatogenesis, histone is replaced by which of the following to allow better packing of the condensed chromatin in the head of the spermatozoon?

A. Inhibin

B. Prostaglandin E

C. Testosterone

D. Protamine

E. Androgen-binding protein

Answer 10

D. Protamine