Lecture 23

Question 1

The cells that will give rise to the male gametes (sperm) are called _________.

These cells first originate within the primary _______ of the embryo (wk____) and migrate to the ________ of the ________ yolk sac.

Answer 1

primitive germ cells
ectoderm
2
mesoderm
extraembryonic

Question 2

From the yolk sac the _______ germ cells migrate through the _________ and finally come to rest in the ______ of the dorsal body wall adjacent to the ____ vertebra (wks ____).

Answer 2

primordial
primitive gut tube
mesentery
T10
4-6 weeks

Question 3

This migration causes adjacent epithelial cells in the dorsal body wall to______ and ultimately form swellings called ________ that represent the ______

Answer 3

proliferate
genital ridges
primordial gonads

Question 4

In both males and females the primordial germ cells undergo further mitotic divisions within the _______ and then commence__________.

___________: the process that converts germ cells to mature male and female gametes
( _________ and ______ respectively)

Answer 4

gonads
gametogenesis

Gametogenesis

spermatozoa
oocytes

Question 5

Males: ________ germ cells remain dormant from the ____ th wk of embryonic development until puberty (approx. age 13).

At puberty the seminiferous tubules mature and the germ cells differentiate into spermatogonia.

Answer 5

primordial

Question 6

The timing of these processes differs in the two sexes:

Males: ________ germ cells remain dormant from the 6th wk of embryonic development until puberty (approx. age 13). At puberty the seminiferous tubules mature and the germ cells differentiate into spermatogonia