Bears repeating, and needs repeating.
You'd think the difference between an egg and an embryo would be clear as a bell. But, pro-choicers love to confuse the distinction, especially those scientists who have an interest in creating a human life for the purpose of destroying it. They will be the first to jump on pro-lifers who don't have tiny facts close at hand, but they, themselves, have constructed an entirely unrealistic overview of conception.
As I wrote in another thread, even intelligent, renowned scientific writers are guilty of espousing this unbelievably shoddy thinking when it serves their purposes.
I really get mad when people who want to mold opinions say that apples are oranges. They try to win an argument, that they are afraid they will lose, by changing definitions.