Human reproduction consists of

three processes: fertilisation,

the development of the embryo and

birth.

Fertilisation occurs when a spermatozoon and an ovun join together to create a zygote, a cell which will become a new human being.

The ovum is usually fertilised in the Fallopian tube and it travels down.

The development of the embryo is the period between fertilisation and birth. It lasts approximatly nine months.

It lasts 3 trimesters:

The zygote develops into an embryo ,which travels to the uterus.

The embryo will be protected by. the amniotic sac ,a bag filled with amniotic fluid.

The placenta is an organ attached to the uterus and joined to the embryo through the umbilical cord.

The embryo and the mother exchange subtances through the placenta.

In the second trimester:

• The embryo is called a foetus.

• Its organs start to develop.

• The foetus develops a face and moves for the first time.

The foetus continues to grow and mature.

• In the seventh month of pregnancy, it is able to survive outside the womb if it is born prematurely.

• In the ninth month the foetus changes downward in preparation for birth.

The walls of the mother´s vagina and uterus begin to dilate, the uterus contracts,

The anmiotic sac breaks

The baby and the placenta leave the mother´s body.

When the baby is born:

the umbilical cord is cut it leaves a scarf called the tummy button.

1.What are the three processes of human reproduction?

2.Where is the ovum usually fertilised?

3.How many months does the development of the embryo last?

4.What is the name of the organ attached to the uterus?

5.How is the embryo called in the second trimester?

6.In the third trimester the embryo …

7.What is the scarf caused by the umbilical cord called?