Gametogenesis
Questions
Name: Shaylah Penn
Date: 11/07/2024
1. After which meiotic division in gametogenesis does the germ cell become haploid?
It becomes haploid at the end of the first meiotic division.
2. What differences are there between the meiotic divisions in a developing sperm and
those in a developing ovum?
The meiotic divisions in the developing sperm are equal. The meiotic divisions in the
developing ovum are unequal because they produce polar bodies and a single large
ovum.
3. What hormone do Leydig cells secrete?
Leydig cells secrete the male sex hormone, testosterone.
4. What changes must a spermatid go through to become a spermatozoan?
The spermatid must go through spermiogenesis to become spermatozoa. This process
includes elongation of the nucleus and cytoplasm of the spermatid; condensation of the
nucleus in the head of the sperm and formation of acrosomal cap; formation of flagellum
that extends toward the lumen of the tubule; and an extensive shedding that pinches off
and appears as dark residual bodies near the lumen of the tubule. When the spermatids
are full spermatozoa the head remains attached to a Sertoli cell.
5. What are some of the major structures of a mature sperm?
Majot structures of a mature sperm include the following: the head; the neck; the
midpiece; the acrosome; the nucleus; and the tail.
6. Compare the nurse cells (Sertoli cells) in the mammalian testis with nurse cells (follicle
cells) in a mammalian ovary.
Sertoli cells are tall columnar cells that extend from te\he basement of membrane to the
lumens of the tubule. Their nucleus are irregularly shaped and contiguous making thema
an unbroken ring around the tubule. The germ cells sit nested in the indentions of the
Sertoli cells and the Sertoli cells function to support and nourish the germ cells. These
cells are also responsible for translocation of developing sperm toward the lumen and
the release of the sperm. They create the blood-testis barrier. Follicle cells become
cuboidal and columnar and they increase in number. The follicle cells secret a fluid
(liquor folliculi) which accumulates in the spaces between the follicle cells. The egg sits
on the follicle cells like a hummock. The follicle cells convert the fluid to estrogen.
7. What is the zona pellucida?
The zona pellucida is the translucent area surrounding an egg.
8. What cells make up the corona radiata?
Follicle cells make up the corona radiata.
9. What is the ovum doing during the primary oocyte stage
The ovum is being grown since the primary oocyte stage is a period of growth.