What is the primary function of genes?

The primary function of genes is to determine traits. Genes are segments of DNA that carry the instructions for the development, functioning, growth, and reproduction of all living organisms. They encode the information necessary to build proteins, which are critical for the expression of traits. For example, genes can influence characteristics such as eye color, height, and various physiological functions, by determining how proteins are produced and how cells function.

While energy production, structural functions, and cell reproduction are all important biological processes, they are not the primary role of genes themselves. Instead, proteins that are expressed from genes carry out these functions within the organism. However, it is the genes that ultimately provide the blueprint for these functionalities by influencing which proteins are made and in what amounts.