Repeating the that mantra that Life begins with conception is to confuse the terms and confuse the issue. Adding in the scientific definition of living does us less than no good. Do we have absolute protection for all living things? This goes beyond even PETA territory into Jainism. Jains sweep the road ahead of them to avoid stepping on bugs. They're alive after all.
Every individual in whatever stage of the human lifespan should be recognized as a "person" in law; otherwise, any socially disfavored individual or community (blacks, Jews, children, the autistic, the congitively impaired, alcoholics, the obese, what-have-you) can be excluded from the recognition of "human rights," the most fundamental of which is the right to simply go on living.