A gene is the basic physical and functional unit of heredity. In its simplest form, a gene is a segment of DNA that contains the instructions for making a specific protein or set of proteins. These proteins perform various functions in the body, such as building cells, regulating chemical reactions, and transmitting signals.
Genes are passed down from parents to offspring and determine many of the traits and characteristics that make each individual unique. Each gene has a specific location on a chromosome, and humans have approximately 20,000-25,000 genes.
In summary, a gene is a piece of DNA that provides the code for a particular protein, influencing how our bodies develop and function.