Origins of body forms 1

Question 1

Define gametogenesis

Answer 1

Is the formation of male and female gametes by spermatogenesis and oogenesis

Question 2

What is spermatogenesis

Answer 2

Formation of complete motile spermatozoa from primordial germ cells (spermatogonia)

Question 3

Where does spermatogenesis occur

Answer 3

In seminiferous tubule of testis

Question 4

When does spermatogenesis start and end

Answer 4

Starts at puberty and ends at old age

Question 5

What is the nature of the spermatogonia cell

Answer 5

Diploid (46)

Question 6

What results in the growth of spermatogonia (44xy), what is the nature of the cell

Answer 6

Primary spermatocytes, diploid (46)

Question 7

List the steps of primary spermatocyte maturation

Answer 7

1ry spermatocyte (diploid, 46)
|
| Meiosis 1
|
v
2ry spermatocyte (haploid, 23)
|
| Meiosis 2
|
v
Spermatid (haploid, 23)

Question 8

What are spermaids

Answer 8

Immobile, haploid sperm cells

Question 9

What is the process of transforming a spermatid to a spermatozoa

Answer 9

SperMIOgenesis

Question 10

How many spermatozoans are produced from 1 primordial germ cell

Answer 10

4

Question 11

What is the normal sperm count for a fertile male

Answer 11

100 million/ml or 300-500 million/ ejaculate

Question 12

What is oogenesis

Answer 12

Process of differentiation of a mature oocyte from primordial germ cells (oogenia)

Question 13

When does oogenesis begin

Answer 13

3rd month of intrauterine life till birth
-pause-
then after puberty at each ovarian cycle and after fertilization

Question 14

When does oogenesis end

Answer 14

At menopause

Question 15

What are the 2 prenatal stages

Answer 15

Proliferation and growth

Question 16

What are the 3 postnatal maturation stages

Answer 16

1st maturation division and 2nd maturation division (at fertilization)

Question 17

What is the nature of oocytes at birth

Answer 17

All oocytes are primary oocytes (diploid, 46)

Question 18

What happens to 1ry oocyte at puberty/ ovarian cycle

Answer 18

1ry oocyte undergoes meiosis 1 and becomes 2ry oocyte (haploid, 23) + polar body

Question 19

What happens to 2ry oocyte if fertilization occurs

Answer 19

2ry oocyte undergoes meiosis 2 and becomes mature ovum (haploid, 23) + 2nd polar body

Question 20

what may occur die to long meiotic division process

Answer 20

High frequency of meiotic error (ex: trisomy 21)

Question 21

What occurs during menstruation in terms of ovarian follicles

Answer 21

Graafian follicle ruptures, releasing 2ry oocyte

Question 22

Define ovulation

Answer 22

Rupture of graafian follicle and discharge of 2ry oocyte

Question 23

What is the onset of ovulation

Answer 23

14th day

Question 24

What happens to the ruptured graafian follicle if 2ry oocyte is fertilized

Answer 24

Follicle is luteinized under the effect of LH becoming a corpus luteum

Question 25

What is the function of corpus luteum

Answer 25

Production of progesterone in the first 3-4 months of pregnancy to increase the lining thickness of the uterus till placenta is formed

Question 26

What happens to the ruptured graafian follicle if 2ry oocyte is not fertilized

Answer 26

It undergoes fibrosis