​How did it start?

• ​Ordinarily, the process of human development starts when a sperm cell meets an egg cell inside the woman's body; they join up and make a fertilized egg. It moves into the womb, an organ in the woman's body, to grow into a baby.

​When a ​woman has a baby growing inside her, she is pregnant. The baby lies in the mother's womb for about 9-10 months, and takes food and oxygen from her body.

Human Stages of Development​

Infancy

• ​is the stage from birth to age 2.

• during this stage​, an infant grows quickly and the baby teeth appear. The nervous system is developed and the child starts to walk.

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​Childhood

• ​is another period of fast growth.

• ​it lasts from age 2 until puberty.

• ​the baby teeth are replaced by permanent teeth.

• ​the muscles become more coordinated with which one can do more difficult activities.