Under examination is whether embryos should be produced in such large quantities, a procedure that is repeated because their implantation is not always successful the first or second time.

The loss of the corpus luteum can be prevented by implantation of an embryo: after implantation, human embryos produce human chorionic gonadotropin (hCG).

The embryo inside each seed produces leaves, or cotyledons, when germinated.

The embryo then produces invasive chorionic tissues that grow between the cells of the uterine lining till they can absorb nutrients from maternal blood vessels.

Parthenogenesis occurs occasionally in chickens and turkeys through doubling of haploid cells to diploid; most embryos produced in this way die early in development.

TWIN FISSION: A method of splitting an embryo into two parts to produce identical twins.

The embryos with the mutated gene produced defective B.M.P. receptors, which were deaf to the suicide signal.

The embryo and fetus produce huge numbers of cells.

The developing embryo produces a young shoot, the sporophyte.

So, even if you're using the most sensitive test, your embryo may not produce a positive pregnancy test right away.