When does life end?
Surely I have the right to chop off my own hand, or something more extreme like killing myself.
When a bullet enters one's brain, surely the human is dead, but the body is not yet dead. The cells live on.
If I chop off my hand, I kill a few cells where I made the cut, but the hand does not die right away.
If I remove some cells from my body, I do not necessarily kill them. If they die because they lack the ability to nourish themselves without me, than they were merely a part of me.
When does life end?
Life does not end. The scientific view, that life is a continuum, with no beginning or end, is the only valid view, in my opinion. As to the religious view (life begins at conception), well people are entitled to believe what they want. The problem comes when they try to impose such religious definition upon rest of the society (by trying to ban abortion etc.).
Now, when it comes to human life, I think most agree that human life ends once the brain is dead. But exactly when human life begins, again, we don't know. Scientists don't know and that means society doesn't know.