1. EMBRYOLOGY

2. Definition:-
Embryology is a science which is about the
development of an embryo from the
fertilization of the ovum to the fetus stage.

3. Meiosis is the first step in gametogenesis: separation of homologous
chromosomes into haploid daughter cells
Spermatogonia and oogonia are the germ cells that will eventually develop
into the mature sperm or egg
Primary spermatocyte or oocyte: the first step in this development is the
duplication of homologous chromosomes to get ready for meiosis
Secondary spermatocyte or oocyte:
the first meiotic division separates
the homologous chromosomes from
each parent
Spermatids or eggs: the second
meiotic division separates the 2
chromatids and creates 4 haploid
cells
In males, this eventually produces 4
sperm cells by the process of
spermiogenesis. In females, it
produces 1 egg and 3 polar bodies.
This allows the egg to retain more
cytoplasm to support early stages of
development

4. Gametogenesis
• Gametes develop in the
gonads (sex cells)

5. Definition:-
Gametogenesis, the development of diploid
germ cells into either haploid eggs or sperm,
(respectively oogenesis and spermatogenesis)
is different for each species but the general
stages are similar

6. •Their are 2
types of
gametogenesis

7. Spermatogenesis
• Production of sperm in
the testes
• Produce 4 sperm from
one cell
• Meiosis

8. Male Reproductive System

9. Oogenesis
• Production of eggs in
the ovary.
• Produce 4 eggs by
meiosis
• One egg cells is
functional.
• Three egg cells are
nonfunctional.
• The are known as polar
bodies

10. Female Reproductive System
Sperm Enters the
vagina 1st
Sperm must
pass through
the uterus 2nd
Lastly the
sperm and egg
meet here for
fertilization

11. Oviduct
Fertilization occurs here

12. Zygote
• Zygote is a fertilized
egg.
• A fertilized egg
becomes an embryo as
soon as the first
cleavage occurs.

14. Internal Ferilization
• Chance of zygote
survival is increased
greatly

15. External Fertilization
• Zygotes chance of
survival decreases
significantly