Although the word chondroblast is commonly used to describe an immature chondrocyte, the term is imprecise, since the progenitor of chondrocytes (which are mesenchymal stem cells) can differentiate into various cell types, including osteoblasts
choanocyte. n. 1. (Zoology) any of the flagellated cells in sponges that maintain a flow of water through the body. A collar of protoplasm surrounds the base of the flagellum. Also called: collar cell.
Choanoflagellates are a type of protozoa, meaning a unicellular eukaryote (complex-celled organism), in contrast to other unicellular organisms such as bacteria and archaea.