Religious question:
When is the zygote/blastocyst/fetus invested with a soul?

Secular question:
At what point does it become human?

Is a zygote human if fertilization occurs outside the human body? (Is DNA enough to define a human?[The answer is no])

If not, does it become human once implanted in a uterus?

What makes a human different than other animals and when during ontogeny does this difference occur?