Identical twins result from the division of a single fertilized egg (zygote) into two separate embryos.
Fertilization: A sperm fertilizes an egg, forming a zygote with a complete set of chromosomes (half from the mother and half from the father).
Early Development: The zygote undergoes a series of divisions through a process called mitosis. These divisions result in a multicellular structure known as a blastocyst.
Inner Cell Mass (ICM) Formation: The blastocyst contains an inner cell mass (ICM), a cluster of cells inside the outer layer. The ICM is pluripotent, meaning it has the potential to develop into any cell type in the body.