Difference in between Identical twins and fraternal twins
Same Same but Different
Pregnancy start when a sperm fertilises an egg. This fertilised egg is called a zygote. Usually one egg is released from a ovary but sometimes a woman’s ovary might release two eggs. These two eggs are fertilised by two separate sperms. Thus two zygotes are formed resulting in conception of twins. These twins are called fraternal twins or dizygotic twins (meaning two zygotes) or non-identical twins. The placenta provides oxygen and nutrients to the developing babies inside the womb. These twins have separate placentas and umbilical cords. The technical name for this is dichorionic. Fraternal twins can be of the same or opposite sex and their genes are different.
Sometimes a fertilized egg splits within a few days of conception to produce genetically identical twins. Because these twins come from one zygote, they are also known as monozygotic. Identical twins are of the same sex. Identical twins can be of three types: About one-third of identical twins split soon after fertilisation and form completely separate twins. Like fraternal twins, these twins have separate placentas. The other two-thirds split after they attach to the wall of the womb. As a result, they share a placenta. The technical name for these is monochorionic. In a very small number of identical twins, splitting might happen even later. In this case, both twins share an inner sac, called the amnion, in addition to sharing a placenta. The technical name for this is monoamniotic twins. They’re often called MoMo twins.