Without preamble this exchange occurs.
Hubby: If a baby is really part of its mother then you have four arms right now.
Me: And two heads.
Hubby:And if the baby is a boy you've got a couple of testicles.
Me:And if its a girl four ovaries.
Hubby: How can something with different DNA be part of you? Is a parasite part of you?
He's grading papers right now. He earlier commented on the remarkable fact that the human genome consists of a prime number of chromosomal pairs (23).