THE FUNCTION OF GENES

The DNA consists of a long combination of four different nucleotide bases (chemicals). The four chemicals are adenine, thymine, cytosine, and guanine (A, T, C, and G). These chemicals can form many possible combinations. Different combinations of the letter ATCG will give people different characteristics. The DNA patterns are also the codes for manufacturing proteins.

Proteins are the building blocks for everything in your body. Proteins made up bones, teeth, hair, earlobes, muscles and blood. Those proteins help our bodies grow, work properly, and stay healthy. Scientists today estimate that each gene in the body may make as many as 10 different proteins. That's over 300,000 proteins!

Genes also come in pairs like chromosomes. Each living organism has two copies of each of genes, and each parent passes along just one copy to make up the genes an offspring have. Genes that are passed on to offspring determine many of its traits, such as hair color and skin color.

For example, Kelly’s mother has one gene for black hair and one for brown hair, and she passed the brown hair gene on to Kelly. If her father has two genes for brown hair, that could explain her brown hair. Kelly ended up with two genes for brown hair, one from each of her parents.