What the Reproductive System Does

1Why living things reproduce

All living things reproduce: they make new living things of their own kind. Cows have calves, bean plants make seeds, and people have babies. Without reproduction, every kind of living thing would slowly die out.

The reproductive system is the group of organs that makes reproduction possible. Boys and girls have different reproductive organs. These organs start to work at puberty, the time when a child's body begins to change into an adult's body.

2Two kinds of sex cells

• In males, two organs called testes make sperm cells. A sperm cell is one of the smallest cells in the body.
• In females, two organs called ovaries hold egg cells (also called ova; one is an ovum). The egg cell is the largest cell in the human body.

3From one cell to a baby

A baby begins when a sperm cell from the father joins an egg cell from the mother, inside the mother's body. This joining is called fertilisation. The fertilised egg attaches to the thick, soft wall of the uterus (the womb) and grows there.

The growing baby gets food and oxygen from the mother through the placenta and the umbilical cord. Your belly button shows where your cord was joined to you. A pregnancy lasts about 9 months (about 40 weeks). The baby gets half of its features from the mother and half from the father, which is why children look a bit like both parents.

A pregnant mother should eat well, avoid alcohol and smoking (they pass to the baby), and go for regular antenatal check-ups at the health centre.

4Planning a family

Raising a child is a big responsibility. Each child needs food, clothes, health care, school, time and love. Family planning means that a couple decides together how many children to have and when to have them, leaving time between births.

Family planning does not mean having no children. It helps because:

• the mother has time to recover between births, so mother and children stay healthier;
• parents can give each child enough food, care and schooling;
• families, and the whole country, can fight poverty more easily.

These are decisions for grown-ups. Children and teenagers are still growing and are not ready to be parents.

Try it yourself

Try each one on your own first, then tap Show answer to check.