Monozygotic semi-identical (polar) twins are a special type of twin. In science it is called an intermediate type between monozygotic (identical) and dizygotic (non-identical) twins. They occur very rarely, and the process of their formation is very complex. Together with the egg, even before fertilization, a polar body, a small cell that usually dies off, … Читати далі “Fertilisation of a Normal Egg and a Polar Body: An Uncommon and Puzzling Occurrence”