What are genes?
A gene is a sequence of nucleotides in DNA that transcribe a functional RNA fragment and is usually found in specific regions of the genome. They are considered the basic unit of heredity, as a gene carries the information that allows a protein to be produced or its function to be regulated, thus determining the characteristics of the individual.
In humans, all individuals have two copies of each gene, except for the genes found on the X and Y sex chromosomes. Genes can undergo mutations, and each variant of a gene is called an allele.
It is a term whose definition has changed over the years as new information has been discovered in the field of genetics.