In rebutting hardcore religious anti-abortionists I often point out to them, to make the point that a zygote is just a cell, that we can now grow animals from skin cells.
And even program those cells to go through meiosis and thus make haploid cells that can be merge (i.e. “fertilized”.)
Finally PBS Terra made a video that points this out, and I plan on embedding it in my rebuttals: