The cytotrophoblast, deep inside, consists in an inner irregular layer of ovoid, single- nucleus cells. This is also where intensive mitotic activity takes place. In the periphery the syncytiotrophoblast forms a syncytium, i.e., a multi-nucleic layer without cell boundaries that arises from the fusion of cytotrophoblast cells.
Define Aryl group. Aryl group synonyms, Aryl group pronunciation, Aryl group translation, English dictionary definition of Aryl group. n. A compound containing benzene or another aromatic hydrocarbon, or a univalent group derived from such a compound by removal of a hydrogen atom attached...
Definition: Mercaptan is an organic sulfur compound composed of an alkyl or aryl group and a thiol group. General formula: R-SH where R is an alkyl or aryl group. Examples: The amino acid cysteine is a mercaptan.