In his view, a fertilised ovum is a potential human being.

That did not mean a fertilised ovum is not unborn life, he argued.

I had a fertilised ovum implanted in my peritoneal cavity.

A fertilised ovum from the oviduct of a hen.

Four vertical sections of the fertilised ovum of the toad, in four successive stages of development.

Stem-cell of one of the echinoderms (cytula, or "first segmentation-cell" = fertilised ovum), after Hertwig.

That these unicellular ancestral forms did once exist follows directly from the phenomena which we perceive every day in the fertilised ovum.

While the Church leans strongly to the position that the fertilised ovum is a human person, she has not committed herself expressly to that position.