Flashcards in Lec: 64 Early Embryogenesis Deck (13):
until the end of the 8th week
2-cell stage to morula
days 4 - 6
week 9 to birth
- Completes first meiotic division.
- Arrests at metaphase of meiosis II.
- Oocyte has a haploid number (1n) of chromosomes but is diploid in DNA content (2d).
- It is 23, X.
Uterine Tube Mucosa
-Peg cells secrete nutritive material for ovum.
-Ciliated cells move fluid down the tube.
Ovum viable in female reproductive tract
• Consists of a nucleus and a tail
• Contains a haploid number (1n) of chromosomes and is haploid in DNA content (1d). 23, X or 23, Y
- Gain motility
From contact to mingling of genetic material
Takes 24 hours
1. Penetration of Corona Radiata
2. Penetration of Zona Pellucida
3.Ovum Sperm Membrane Fusion
4. Male Pronucleus forms
5. Pronuclei replicate their DNA.
6. Pronuclear membranes degenerate
7. Chromosomes line up for mitosis and first cleavage