Monozygotic refers to twins that develop from a single fertilized egg, or zygote, which splits into two embryos. This process results in genetically identical siblings, sharing the same DNA. Because they originate from the same egg, monozygotic twins often have similar physical traits and may even share certain personality characteristics. These twins are commonly known as identical twins. They can provide valuable insights in scientific research, particularly in studies related to genetics and environmental influences on development. Understanding monozygotic twins helps researchers explore the roles of heredity and environment in shaping individual differences.