Modified blastula that is characteristic of placental mammals.
Note: It has an outer cell layer, known as the
trophoblast, which participates in the development of the placenta, and an inner mass of cells in the
blastocoel, which develops into the embryo.
Source:
PAC, 2016, 88, 713. 'Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)' on page 730 (https://doi.org/10.1515/pac-2015-1202)