Cancer genetics family tree

The diagram shows how genes are passed on from a parent to a child. At the top of the diagram are images to represent the parents. The man is made of two colours to show that he has a gene mutation in half of his genes. The woman is a single colour and has no gene mutation. Below the parents are four smaller images representing their children. There are two sons and two daughters. Two of the children have inherited a gene mutation from their father and a normal gene from their mother. Like their father they are made of two colours. The other two children have inherited normal genes from their father and mother. They are shown in one colour.