Genetics

The information that results in plants and animals having similar characteristics to their parents is carried by genes which are passed on in the sex cells (gametes) from which the offspring develop.
Different genes control the development of different characteristics.
The nucleus of a cell contains chromosomes. Chromosomes carry genes that control the characteristics of the body.

Below is a typical human body cell. Inside the nucleus of the cell are 46 strands of a chemical called DNA. There are actually 23 pairs. 23 chromosomes we get from our father (in a sperm cell) and 23 we get from our mother (in an egg cell).

When a sperm cell and egg cell fuse (fertilisation) a unique individual is created which has a mix of chromosomes from each parent.

Each chromosome is made up of sections called genes. There are thousands of genes on a single chromosome. The genes contain all the information which is needed for cells to do their jobs, e.g. the cells control characteristics such as hair and eye colour and have a strong influence on weight and height.

Just about everything about you is controlled or influenced by your genes. As you have genes from both your parents your characteristics will be a mixture of theirs. Some of your fathers genes will determine some things about you and some of your mothers genes will determine other things. The genes that take control are said to be dominant, e.g. brown eyes genes are dominant over blue eye genes.