opposed to di-zygotic twins are always of the same sex because they develop from the same ovum, which simply splits in the early stages of mitosis (cell division) which forms two individuals which carry the exact same genetic data.
opposed to di-zygotic twins are always of the same sex because they develop from the same ovum, which simply splits in the early stages of mitosis (cell division) which forms two individuals which carry the exact same genetic data.