gonadal development Flashcards Preview

ANATOMY KAPLAN FOR THE USMLE > gonadal development > Flashcards

Flashcards in gonadal development Deck (23):
1

During which weeks the gonads develop as indifferent ?

4 - 7 weeks of development.

2

The indifferent gonads develop from ?

Urogenital ridge (intermediate mesoderm)

3

Primordial germ cells arise from the walls of ?

The Yolk sac

4

Which are the components of the indifferent gonad ?

1)Primordial germ cells
2)Primary sex cords
3) Mesonephric and the paramesonephric duct

5

Who has to induce the differentation of the indifferent gonas in the urogenital ridge ?

The primordial germ cells from the yolk sac

6

Wolfian estrucutres are related to the male or female ?

Male

7

How the indifferent gonads differentiate to testicles ?

Y chromosome= SRY gene which encodes testes determinating factor (TDF)

8

How secundary chracteristics of a male develop ?

Leydig cells produce testosterone

9

Which factor inhibits the development of female structures ?

The mullerian inhibitor factor from sertoli cells

10

Meiosis is a type of special division to form ?

male and female gametes

11

Primary spermatocyte is 46, 2N true or false

False
Its 46, 4N due to the replicated DNA.

12

Secondary spermatocyte is 23, 2N true or false ?

True
After meiosis 1, one pair of chromosomes goes to each cell.

13

Which events occur during meiosis 1 ?

Synapsis
Crossover
disjunction without centromere splicing

14

Which events occur during meiosis 2 ?

No synapsis and crossover
Disjunction with centromere splicing

15

Spermatogenesis in males begins at ?

Puberty

16

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.

17

A female each month develops an ?

A primary oocyte that completes meiosis 1 and becomes an secondary oocyte arrested in meiosis 2

18

Females from one primary oocyte produces ?

One ovum

19

Males from one primary spermatocyte produces ?

4 spermatids that undergo spermiogenesis to differentiate to spermatozoa

20

A female each monthly ovulation will produce ?

One secondary oocyte

21

which step is necessary to complete meiosis 2 from secondary oocytes ?

Fertilization

22

Why females develop polar bodies during gametogenesis ?

Due to unequal divisions of cytoplasm

23

A somatic cell is 46, 4n true or false ?

False , a somatic cell has two pairs of single chromosomes being 46, 2N