The gene that is responsible for twins is a Mendelian dominant - you can tell, because they're like peas in a pod.
Spoiler
No, not really. I just made that up for a cheap laugh.
@ecar3483 wrote:
Lol. When my daughter was asked constantly if they were twins,
she replied that because she had the twin pusher,
she had to borrow one from the neighbours to fill it
