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...
Ester Definition. An ester is an organic compound where the hydrogen in the compound's carboxyl group is replaced with a hydrocarbon group. Esters are derived from carboxylic acids and (usually) an alcohol. While carboxylic acid has the -COOH group, the hydrogen is replaced by a hydrocarbon in an ester.