The U.S. Constitutionâs 10th Amendment is arguably the most important of all the amendments in the brilliant document that helped shape the United States.
Not even identical twins have the same DNA--although theirs would be far closer than anyone else's. DNA changes over time. Odds of two siblings having the same DNA who did not split from the same zygote are vanishingly small.
Identical twins are genetically identical, so are always the same sex. On the other hand, you could have non-identical twins of the same sex. If a pregnancy scan clearly shows a boy and a girl then you can be sure that the twins are non-identical.