A petri dish full of embryos is not a pool of people and an unwanted embryo is not a person. For an embryo to be called a person, their parents must make that designation. No one else has the right to do so.
When an intermediate premise assumes the conclusion, we have circular reasoning. Highly irrational.
Translated to expose the circle, you appear to be saying that a very young human life is not capable of being defined as protectable human life except by older human life which has already been designated as protectable human life by other human lives that have also been designated as protectable human life AND capable of judging the protectability of human life by yet other human life deemed as protectable human life by (insert infinite regression here) ....
Confused reasoning at its finest. You are begging the question of what human life is, deferring answering of that question to an infinite regression which never answers it. As Spock would say, highly illogical.
Stop at this point. First, human life is determined by adults. Very young human life includes fresh skin calls after division. They obviously can not make decisions, but can, with the help of some scientists become adult humans and then at that point they can make decisions.
"You are begging the question of what human life "
The question isn't, "what is human life?" The question is "what is a person?" Personhood is determined by those who have reached the age of reason. ie. adults