The biological factor that is unique to each individual is the

The biological factor that is unique to each individual is their DNA. DNA (Deoxyribonucleic Acid) is a molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms. It is found in the cells of every living thing and contains the genetic information that determines the traits and characteristics of an individual, such as eye colour, blood group, and other physical and biological attributes. Each individual has a unique sequence of DNA, which is determined by the combination of genetic information inherited from their parents. DNA is responsible for passing on hereditary traits from one generation to the next and is the main factor that makes each individual unique.