Lecture 12: Developmental Biology Flashcards
1
Q
What breaks through pellucida & prevents cross-species fertilization?
A
acrosome
2
Q
What are the 4 components of sperm?
A
- acrosome
- head -> nucleus
- neck -> mitochondria
- flagellum -> motility
3
Q
What are the functions of the head of the sperm?
A
- breaks through the egg
- houses nucleus
4
Q
What are the components of an egg?
A
- evenly distributed yolk = isolecithal
- small amount of yolk = microlecithal
4
Q
What is the only thing males contribute to the embryo?
A
a nucleus
5
Q
What does cleavage form?
A
16 cell morula
6
Q
A
7
Q
What is cleavage?
A
- solid ball of totipotent cells
- forms blastula (hollow ball stage)
8
Q
What does a blastula surround?
A
blastocel
9
Q
What are the 2 layers of the blastula?
A
- inner cell mass -> embryoblast
- outer layer -> trophoblast
10
Q
A
11
Q
What part of the blastula becomes the embryonic placenta?
A
trophoblast
12
Q
A
12
Q
How does the prophoblast invade the endometrium?
A
grows roots to cause damage
13
Q
How long does it take between the time of ovulation to the time of implantion?
A
about 7 days
