To keep it simple and not get too technical, fraternal twins are from two eggs and two sperm that independently combine to produce a baby. Identical twins come from a single egg and sperm that divide to create two separate children. Gender is controlled by the males sperm and whether it contains the male genetic X chromosome. Since identical twins have the same sperm their genetic makeup is exactly the same (same egg and sperm used in development). Fraternal twins have two separate sperm and therefore it is possible one has the X chromosome and other does not.
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I dont think there is such a thing as paternal twins...perhaps you are thinking of fraternal twins. In that case, they are not identical twins, they do not look the same and they can be different sexes.
Identical twins are the result of a single fertilized embryo splitting in two at an early stage and forming two viable embryos. As such, identical twins have identical DNA. Fraternal twins are the result of two distinct fertilized embryos being viable. As such, they have different DNA. They could even be different sexes.
Fraternal twins can be the same sex or opposite sexes. It doesn't matter.
Identical twins are two children born of one egg and one sperm, that splits early on and then separates, each half then developing into a full organism. Since they came from only one egg and one sperm, their genes will be identical. Fraternal twins are two children born of two eggs and two sperms, each of them developing into a full organism. Since they did not come from only one egg and one sperm, their genes will be different. They could even be opposite sexes.
sexes