👉 Homozygosis is a genetic condition that refers to two identical twins having the same traits, typically in terms of physical development and behavior. This can occur when one twin has an abnormal gene (the "carrier") and the other twin does not have it, creating a balanced set of chromosomes for each individual. In this case, there are no inherited disorders or genetic defects. Homozygosis is often seen in families where both parents share an identical chromosome (usually 21 chromosomes