Fertilisation and the stages of prenatal development.

Question 1

Define Fertilization

Answer 1

The fusing of a sperm and an egg cell (called a Zygote). This process is known as conception and marks the beginning of conception.

Question 2

Identify and Outline the Three prenatal stages, with two developments that occur during each stage.

Answer 2

GEF:

Germinal: 0-2 weeks
- After three days the zygote consists of 16 cells
- The zygote travels down the fallopian tube and into the uterus

Embryonic: 3-8 weeks
- The embryo is approx. 1.3cm long.
- Blood cells are being made in the liver

Foetal: 9-40 weeks
- Teeth are beginning to form in the lungs
- The eyelids separate into upper and lower lids and the foetus can open and shut its eyes