S3 Gametogenesis Flashcards
1
Q
What happens after the germ cells have colonised the gonad?
A
They
1) Proliferate by mitosis
2) Reshuffle genetically and reduce to haploid by meiosis
3) Cytodifferentiate into mature gametes
2
Q
What determines the sex of the offspring?
A
Whether the sperm (male gamete) contains an X or a Y chromosome.
3
Q
Where does genetic variation come from?
A
Crossing over
Independent assortment
Random segregation (random distribution of alleles among the 4 gametes).
4
Q
Where does spermatogenesis occur?
A
Walls of the semineferous tubules.
5
Q
What is the role of the blood testis barrier?
A
Allows different cells to live side by side
Stops immune system destroying sperm
