Gene << jeen >> is part of a cell that determines which characteristics living things inherit from their parents. Genes determine such features as the shape of a leaf or the sex, height, and hair color of a child.
Every cell has tens of thousands of genes, which occur on threadlike structures called chromosomes. Most genes occupy a specific place on a certain chromosome. Genes cannot be seen with an ordinary light microscope. Scientists investigate the locations and properties of genes with advanced laboratory methods.
Genes produce their effects by influencing chemical and physical processes that control how living things grow, develop, and function. Most genes are encoded within the structure of a chemical called DNA (deoxyribonucleic acid). Each gene is a particular segment of a DNA molecule in a chromosome. However, the genes of some viruses are made up of another chemical called RNA (ribonucleic acid).
