system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: if every person's genome is unique, where along the umbilical cord does the mother's genome end and the child's begin?

The genome is obviously specific to an individual's cells, but the umbilical cord transports nutrients and blood and the like to the child. Is the cord itself the child's genome but what it transports are the mother's?
gpt
All of the umbilical cord contains cells with the child's DNA, and (mostly) all the blood cells it transports are also made with the child's DNA. But the organ the umbilical cord connects to, the placenta, is where the mother's cells and the child's cells interface to exchange nutrients.

Some cells do cross the placenta, so the mother will have bits of her child's DNA in her system, and the child will have bits of the mother's DNA in their system.