Fine.
Is a zygote a human being? No, because it can divide into two zygotes that will eventually form into TWO human beings, twins. Sometimes they divide again to form quads. If a human life begins at conception, how does the 2nd human life of the twins form if it did not form at the moment conception? The only explanation is that an individual life forms sometime after conception during the gestation process.
In fact, the idea of the "moment of conception" is a misnomer since conception is a process, not an event.
A human life is an individual and indivisible lifeform. Therefore from a strictly biological sense, a zygote is not an individual human life.
A human life is an individual and indivisible lifeform.So inoperable Siamese Twins are not human?
How do you defend that using your 'belief' system?