Flashcards in gonadal development Deck (23):
During which weeks the gonads develop as indifferent ?
4 - 7 weeks of development.
The indifferent gonads develop from ?
Urogenital ridge (intermediate mesoderm)
Primordial germ cells arise from the walls of ?
The Yolk sac
Which are the components of the indifferent gonad ?
1)Primordial germ cells
2)Primary sex cords
3) Mesonephric and the paramesonephric duct
Who has to induce the differentation of the indifferent gonas in the urogenital ridge ?
The primordial germ cells from the yolk sac
Wolfian estrucutres are related to the male or female ?
How the indifferent gonads differentiate to testicles ?
Y chromosome= SRY gene which encodes testes determinating factor (TDF)
How secundary chracteristics of a male develop ?
Leydig cells produce testosterone
Which factor inhibits the development of female structures ?
The mullerian inhibitor factor from sertoli cells
Meiosis is a type of special division to form ?
male and female gametes
Primary spermatocyte is 46, 2N true or false
Its 46, 4N due to the replicated DNA.
Secondary spermatocyte is 23, 2N true or false ?
After meiosis 1, one pair of chromosomes goes to each cell.
Which events occur during meiosis 1 ?
disjunction without centromere splicing
Which events occur during meiosis 2 ?
No synapsis and crossover
Disjunction with centromere splicing
Spermatogenesis in males begins at ?
Oogenesis in females start ?
From the 5th month of development, by the time the bay is born she has only primary oocytes but arrested on meiosis 1 until puberty.
A female each month develops an ?
A primary oocyte that completes meiosis 1 and becomes an secondary oocyte arrested in meiosis 2
Females from one primary oocyte produces ?
Males from one primary spermatocyte produces ?
4 spermatids that undergo spermiogenesis to differentiate to spermatozoa
A female each monthly ovulation will produce ?
One secondary oocyte
which step is necessary to complete meiosis 2 from secondary oocytes ?
Why females develop polar bodies during gametogenesis ?
Due to unequal divisions of cytoplasm