Week 1 Objective 1 and 2: list and describe the four phases of gametogenesis Flashcards
1
Q
Phases of Gametogenesis (4)
A
- Extraembryonic origin of germ cells and their migration to the gonads
- Proliferation of germ cells via mitosis
- Reduction of chromosomal number 2n –> n
- Structural and functional maturation of the eggs and spermatozoa
2
Q
1st phase of gametogenesis
A
Extraembryonic Origin of Germ Cells
3
Q
First appearance of germ cells in human embryogenesis
A
- 24 days after fertilization
2. founded in endodermal layer of yolk sac
4
Q
Migration route of germ cells
A
yolk sac –> hindgut epithelium –> dorsal mesentery —> developing gonads
through dorsal mesentery into developing gonads
5
Q
Male gametes =
A
spermatozoa
6
Q
Female gametes =
A
Eggs
7
Q
Teratomas
A
Growths from misdirected and migrating primordial germ cells
Contain mixtures of highly differentiated tissues