11. Gonad Development Flashcards
Where do primordial germ cells arise from?
They arise from the wall of the yolk sac.
What happens at week 4 to the primordial germ cells?
They migrate into the indifferent gonads, which forms in a longitudinal elevation of intermediate mesoderm called urogenital ridge.
What are the 3 things need for the normal development of testes?
The SRY gene on the short arm of Y chromosome, which encodes for the testes-determining factor (TDF); Testosterone, which is secreted by the Leydig cells; and Mullerian-inhibiting factors (MIF), which is secreted by the Sertoli cells.
What factors are needed for the development of ovaries?
No factors are needed; ovaries are the default development of all humans.
What is synapsis?
It is the pairing of 46 homologous chromosomes.
What is Crossing over?
The exchange of segments of DNA.
What is Disjunction?
The separation of 46 homologous chormosomes without centromere splitting.
