Gametogenesis is the process of developing mature gametes (eggs and sperm) through meiosis. Oogenesis involves the development of a primary oocyte into a secondary oocyte over many years in females. Spermatogenesis is the process where spermatogonia develop into spermatozoa in males. Fertilization occurs when a sperm penetrates an egg in the fallopian tube, and their genetic material combines to form a zygote, beginning the process of embryogenesis.

1. Gametogenesis
Ms. Mayuri Patel
Sandra Shroff ROFEL College of Nursing, vapi

2. Gametogenesis
The process involved in the maturation of
the two highly specialized cells,
spermatozoon in male and ovum in the
female before they unite to form zygote, is
called gametogenesis.

3. Oogenesis
 The process involved in the development of a mature ovum
is called oogenesis.
 From yock sac – Primitive germ cells at 3rd
week

4. GERM CELLS
OOGENIA
First meiotic
division
PRIMARY
OOCYTES
46,XX
7 million at
20 weeks
Mitosis
Arrest 1st
meiotic
division upto
puberty
Maturation of
graafian follicle

5. Secondary oocytes
23, X
1st
Polar body
23, X
OVULATION
Not fertilized Fertilized
Degeneration within
24 hours
Completion of second meiotic
division
Female pronucleus
23,X
Second polar
body 23, X

6. Spermatogenesis
 The process involved in the
development of spermatids from
the primorbadial male germs and
their differentiation into
spermatozoa is called
spermatogenesis.

7. GERM CELLS
SPERMATOGONI
A First meiotic
division
PRIMARY
OOCYTES
46,XY
7 million at
20 weeks
Mitosis
1st
meiotic
division
Secondary
Spermatocytes

8. 23, X 23, Y
Second Meiotic
Division
23,
X
Morphological Changes To
Spermatozoa
SPERMATIDS
23, Y23, Y23,
X

10. OVULATION

11. OVULATION

12. OOCYTE TRANSPORT
 At the time of ovulation, the fimbriae move
over the ovary and sweep the ovulatory mass
containing secondary oocyte, into the
infundibulum.
 The ovulatory mass is then guided into the
ampulla through the movements of cilia, and by
muscular contraction of uterine tube wall
(Tubal Peristalsis).
 It has been estimated that the ovulatory mass
takes about 25 minutes to reach the site of
fertilization.

13. SPERM TRANSPORT
 Usually 200 to 500 million sperms are deposited.
 Sperms pass by movements of their tails through
uterus & tubes; assisted by muscular contraction.
 Prostaglandins present in the seminal plasma may
stimulate uterine motility at the time of
intercourse.
 It is not known how long it takes sperms to reach
the fertilization site but the time of transport is
short 5-45minutes.

14. FERTILIZATION
1. Penetration of the Corona Radiata
2. Penetration of Zona Pellucida
3. Penetration of Oocyte Cell Membrane and
Formation of Zygote

16. Contact And Fusion Of The Gemets
Penetration of the zona Pellucida
Releasing of Hyaluronize from acrosomal cap
Sperm touches oolema
Zona reaction & oolema block
Release Of
Cortical
Granules
From Oocytes
Sperm & ovum met
Completion of secondary meiotic division
Female pronucleous 23, X Second polar body 23, X

17. 23, X 23, Y

18. zYGote

19. Sex of child determine by pattern of sex
chromosome supplied by spermatozoon.

20. FERTILIZATION

21. Morula
Mitotic
Division
Resembling like
Mulberry
30 hours after
fertilization
Morula spend 3days in the uterine tube enter the
uterine cavity through the narrow uterine ostium on 4th
day in the 16-64 cell stage.

22. TraNSPor
T
 Slow process
 Controlled by muscular
contraction
 Movement of cilia

23. Form embryo
Form protective &
nutritive
membranes of
embryo