Gestation

Key Stage 3

A diagram showing the final stage of gestation just before the offspring is born.

Gestation is the period of time while offspring are developing in the uterus of a mammal.

Gestation may be referred to as pregnancy.

Gestation starts with conception and ends with birth of the offspring.

The offspring goes through several stages of development:

1. The ovum is released from the ovary.

3. The embryo makes its way to the uterus where it implants itself into the lining of the uterus.

4. The lining of the uterus develops into an amniotic sac, a placenta and an umbilical cord to protect and feed the embryo.

5. The cells specialise and the embryo becomes a foetus.

6. The foetus becomes fully developed and turns itself upside down so it can exit through the vagina head first.


After fertilisation the ovum divides into two cells, then four cells.	This embryo has many cells that have not yet been given a specific job.

The cells in this embryo are being assigned specific jobs as it starts to look more like a human.	Once all the cells have been given their specific jobs it is called a foetus. A this point the offspring is preparing to live outside the uterus.