MEETING GAMETES
Study the following details for a better understanding of gametogenesis and
what happens after it.
1. Process and location
o Male - Spermatogenesis in the testes.
o Female - Oogenesis in the ovaries.
2. Parent cell for gametogenesis
o Male - Primary spermatocyte.
o Female - Primary oocyte.
3. Cell produced after Meiosis I
o Male - Two secondary spermatocytes.
o Female - One secondary oocyte (X) and one (1st) polar body (Y).
4. Cell produced after Meiosis II
o Male - Four spermatids.
o Female  From the secondary oocyte (X): One ovum + One polar
body.
 From the first polar body (Y): Two other polar bodies.
5. What happens to cells produced after Meiosis II?
o Male - Spermatids differentiate into sperms.
o Female - All three polar bodies will degenerate; only the ovum
will survive.
6. When does Meiosis II occur?
o Male - Immediately after Meiosis I.
o Female  For the first polar body: immediately after Meiosis I.
 For the second oocyte: only after a sperm penetrates the
oocyte.
7. What happens during sexual intercourse?
o Male - Sperms are ejaculated from a male's penis into a female's
vagina.
o Female - Sperm from a male swim upwards, from a female's
vagina, through the cervix, into the uterus and then to the
Fallopian tubes.
8. Site for fertilisation
o Male - none.
o Female - In the Fallopian tubes of the female reproductive
system.
9. Product of fertilisation
o Male - none.
o Female - A diploid zygote (containing 46 chromosomes), which
then develops into an embryo.
What happens after sexual intercourse?

Possibility I
o A sperm meets the secondary oocyte and penetrates it.
o Meiosis II quickly occurs in the secondary oocyte, and an ovum
and a polar body is formed.
o The polar body degenerates.
o The nucleus of the ovum fuses with the nucleus of the sperm.
o Fertilisation is successful and a diploid zygote is formed.
o The female is pregnant.

Possibility II
o None of the sperms meet the secondary oocyte. This could mean
ovulation has
 not occurred yet;
 occurred but the secondary oocyte, which can only live for
24 hours, has died.
o
o
o
No fertilisation occurs.
No zygote is formed.
The female is not pregnant; she gets her next period as usual.