Where does life begin? Genesis 2:7 reads:
the Lord God formed the man from the dust of the ground and breathed into his nostrils the breath of life, and the man became a living being.
As the Genesis storyteller understands things, the breath of life entering the lungs of the creature made it a living being.
Its worth noting that in Hebrew, two words in the Genesis story mean breath. In Genesis 1:2 “…and the Spirit of God was moving over the surface of the waters…” the word for breath ( Ruwach ) can also be translated as spirit or wind. Here in Genesis 2:7, the Hebrew word for breath is Nashamah, which can be either breath or spirit. A comparison of parallel usage of both words, Ruwach & Nashamah, in the flood story of Genesis 7, suggests that the words are interchangable, at least in some settings:
15 So they went into the ark to Noah, by twos of all flesh in which was the breath of life .
22 of all that was on the dry land, all in whose nostrils was the breath of the spirit of life , died.
Again, from the perspective of this part of Genesis, the life is connected to the presence of the breath/spirit.
Elsewhere in the Penteteuch, the life is connected to the blood
http://www.biblestudytools.net/OnlineStudyBible/bible.cgi?word=life+blood&section=0&version=nsn&new=1&oq=&NavBook=ge&NavGo=7&NavCurrentChapter=7

TBC