i think everything that concerned our life is related to GOD only him knows when life began and when it will end . Only GOD who makes the plans for our life .everything happened to us is by a destination of GOD

I believe life begins with the first heartbeat of the fetus.

You query is too general, too vague. Equu.. is more defined. Life does begin when the seed accepts first drop of moisture and then the cotlydon emerges to becomes a seedling!