From the moment of conception, the cells grow and divide at an exponential rate. They build proteins, process and metabolize carbohydrates consuming oxygen and releasing carbon dioxide. In that regard, they are indistinguishable from any other living cell on the planet Earth. At what date/time is it alive? Well, if the cells are doing all this growing and dividing from the moment of conception, then how can you argue they are not alive?
But of course the fetus is alive! Why else would we be performing an abortion other than to stop the unborn child from growing further and reaching full gestation? This unborn child is not like a seed in a packet on the shelf in the gardening section at the store, waiting to be planted and watered and put in appropriate soil to begin the process of setting down roots and shooting up stalks. This child is more like the seedling that has established roots and deployed leaves and will bear fruit if left in place for the season. I fear the only reason elective abortion is held by some as permissible while doing the same to a newborn is considered murder is that they cannot see the unborn child with their actual eyes (yet.)
Well, you aren't using the right definition of life.
Here is the basic definition of life:
1. Homeostasis: Regulation of the internal environment to maintain a constant state; for example, electrolyte concentration or sweating to reduce temperature.
2. Organization: Being structurally composed of one or more cells, which are the basic units of life.
3. Metabolism: Transformation of energy by converting chemicals and energy into cellular components (anabolism) and decomposing organic matter (catabolism). Living things require energy to maintain internal organization (homeostasis) and to produce the other phenomena associated with life.
4. Growth: Maintenance of a higher rate of anabolism than catabolism. A growing organism increases in size in all of its parts, rather than simply accumulating matter.
5. Adaptation: The ability to change over a period of time in response to the environment. This ability is fundamental to the process of evolution and is determined by the organism's heredity as well as the composition of metabolized substances, and external factors present.
6. Response to stimuli: A response can take many forms, from the contraction of a unicellular organism to external chemicals, to complex reactions involving all the senses of multicellular organisms. A response is often expressed by motion, for example, the leaves of a plant turning toward the sun (phototropism) and by chemotaxis.
(7. Reproduction: The ability to produce new individual organisms, either asexually from a single parent organism, or sexually from two parent organisms.) This one doesn't really apply to fetuses.
So, give me the weeks that it develops the ability to do all these things, and when those things are present, it is definitely "alive."