11.4 Sexual Reproduction Flashcards
1
Q
How is carbon dioxide and oxygen exchanged across placenta?
A
diffusion
2
Q
How is glucose exchanged across the placenta barrier?
A
facilitated diffusion
3
Q
How is urea transported across placental barrier?
A
diffusion
4
Q
How are antibodies transported across placental barrier?
A
endocytosis
5
Q
How is water transferred across placental barrier?
A
osmosis
6
Q
What are examples of steroid hormones?
A
testosterone, estrogen and progesterone
7
Q
What do testosterone do?
A
cause:
- pre-natal development of genitalia (penis, sperm duct and prostate gland)
- during puberty when hormone level rises, stimulates development of secondary sexual characteristics (testes, penis and pubic hair)
- stimulates sperm production
8
Q
How is polyspermy prevented?
A
Cortical reaction (cortical granules fuse with membrane and release of enzymes to outside causes zona pellucida to become impermeable)
9
Q
What are the stages of fertilizing a human egg?
A
- Arrival of sperm
- Binding
- Acrosome reaction
- Fusion
- Cortical reaction
- Mitosis
