2. • the process by
which gametes
are formed.
• literally
“creation of
gametes.”

3. SPERMATOGENESIS

4. • is the process by which
male primary sperm
cells undergo
meiosis, and produce a
number of cells termed
spermatogonia, from
which the primary
spermatocytes are
derived.

5. • Spermatogonium are the germ cells that will eventually develop
into the mature sperm cell.
• Primary spermatocytes the first step in this development is the
duplication of homologous chromosomes to get ready for
meiosis.
• Secondary spermatocytes the first meiotic division separates
the homologous chromosomes from each parent
• Spermatids the second meiotic division separates the 2
chromatids and creates 4 haploid cells. This eventually
produces 4 sperm cells.

7. OOGENESIS

8. • Oogenesis is the
creation of an ovum (an
egg cell).
• It is the female process
of gametogenesis.
• It involves the various
stages of immature ova.

9. • Oogonium are the germ cells that will eventually develop into
the mature egg cell.
• Primary oocyte the first step in this development is the
duplication of homologous chromosomes to get ready for
meiosis.
• Secondary oocyte the first meiotic division separates the
homologous chromosomes from each parent.
• Eggs the second meiotic division separates the 2 chromatids
and creates 4 haploid cells. It produces 1 egg and 3 polar
bodies. This allows the egg to retain more cytoplasm to
support early stages of development.

10. OOGENESIS

11. DIFFERENCES BETWEEN SPERMATOGENESIS
AND OOGENESIS
S P E M AT O G E N E S I S OOGENESIS
• Four gametes from each • One gamete from each primary
oocyte
primary spermatocyte
• One large gamete + 2-3 polar
• Four small gametes of bodies
equal size • Cytoplasm conserved in one
large gamete - may increase.
• Diplotene relatively short Thus, in the final gamete there
• Functions in fertilization is a large amount of cytoplasm
only after meiosis is • Dipotene very long - dictyate
state
complete
• Often functions in fertilization
before meiosis is complete