shadow71 writes:
I am asking as to whether there is a scienctific definition of when human life begins.
In the U.S. the federal and State legislatures, if drafting a law as to what constitutes the crime of murder, will consult the scientific community in re the definition of human life.
And the scientific community would respond, "When human life begins is a matter of definitions, not science."
But science isn't left entirely out of the equation. If we take as an example your definition that human life begins "when the sperm and egg combine to form 46 human chromosomes that are implanted in the uterus and the human embro is formed," then science can provide a great deal of information about when these things happen.
But science can't give you a definition for when human life begins. Someone else has to do that.
--Percy