A crucial event that determines whether the embryo will develop into a male or female occurs in the second half of week six. If the Y chromosome is present in the embryo's cells, a gene within the ...

"We talked about how egregious a 6-week ban was. A fertilized embryo is three to five days old. It is the size of the pen right there," she said, holding up the ink tip of her pen. "It is not ...