Why do we fall ill?
The human body is made up of millions of cells. These cells are very small and are the basic building blocks of the body. They work together to make sure that all the parts of the body function properly.
Every cell in our body has a specific job to do. For example, some cells produce hormones, which help regulate how our bodies grow and develop. Other cells protect us from germs and other harmful substances.
Each cell has a nucleus, which contains genetic material (DNA). The DNA contains instructions for making proteins, which carry out all the functions of the cell.