Fraternal twins are more common than identical twins. Triplets and other higher-order multiples can result from three or more eggs being fertilized, one egg splitting twice (or more), or a combination of both. A set of higher-order multiples may contain all fraternal siblings or a combination of identical and fraternal siblings. read more
Fraternal Twins vs. Identical Twins Diffen › Science › Biology › Microbiology Fraternal twins are “dizygotic,” meaning that they developed from two different eggs fertilized by two different sperm cells, while identical twins are “monozygotic” i.e., they developed from a single fertilized egg that split. read more
If twins are a boy and a girl, clearly they are fraternal twins, as they do not have the same DNA. A boy has XY chromosomes and a girl has XX chromosomes. Girl-boy twins occur when one X egg is fertilized with an X sperm, and a Y sperm fertilizes the other X egg. read more