Secular reasons for and against legalising abortion

[FatAndFaithless]

So you'd say human life and personhood begin at conception. Where's the 'basic biology' that you're using to justify that?

Basic Biology

I specifically did not say that 'personhood', whatever that means, starts at conception.

Not even close. The first sentence of that link already assumes the embryo is the beginning of human life. The only thing that link seeks to "prove" is that the embryo exists immediately at one cell. The proof of life isn't present at all.