system
Given the following post, respond as if you're commenting on Reddit:
human
Does the placenta have the DNA of the mother or the baby? What about the umbilical cord?
gpt
The placenta is fetal tissue! Very, very early on in development the blastocyst implants in the endometrium of the womb. The outer layers of cells in of the blastocyst become the trophoblast that becomes the placenta, embedding deeper and interfacing with the blood supply of the mother. The foetus essentially builds it's own disposable organ to get what it needs from the mother and aid it its regulation as it develops. It's kinda freakin' cool.

Likewise, the umbilical cord is fetal tissue and isn't sourced from the mother. It's basically just arteries and a vein to connect the foetus to the placenta and, by extension, the mother.