- Life Sciences
an informal term for any living species which appears to be the same as a species otherwise only known from fossils and which has no close living relatives. These species have all survived major extinction events. The coelacanth is an example of a living fossil.
single-celled brown algae found in fresh water and seawater. They have hard, shell-like cell...
the blood circuit from the heart to the lungs and back to the heart.