Life begins at the moment of conception. At that very moment, this little one is begining to grow and divide. Non-living things just don't do that.
At the very instant of conception, a little being is created that has all the genetic material it will ever need in order to live the rest of its life. Its totally unique from any other creature on the Earth (provided it is not a twin).
And yes, I do believe its somewhere around 8-10 weeks that a baby not only looks like a baby, but has a beating heart.