No, a boy and a girl cannot have the same DNA. This is because the sex chromosomes, which determine gender, are different in males and females. Males have an X and a Y chromosome (XY), while females have two X chromosomes (XX). This difference in chromosomes means that a boy and a girl will always have at least one distinct chromosome, making their DNA different.
While identical twins share the same DNA, they are always the same sex because they develop from a single fertilized egg. Fraternal twins, on the other hand, develop from two separate eggs fertilized by two different sperm. They are no more genetically alike than any other siblings, and therefore can be different genders.
In summary, a boy and a girl cannot have the same DNA due to the difference in their sex chromosomes.
