Expert: Walter Hintz - 9/14/2006

Question
What does it mean to be an "organism"? The cellular slime mold Dictyostelium discoideum exists initially as a collection of separate cells moving over the forest floor. In times of starvation, these cells come together to form a single "slug" that moves to more fertile territory. Eventually it will change into a new structure that will throw off separate cells again. Is "Dicty" an organism or a group of temporarily cooperating cells?  

Answer
In my definition anything that exhibits life activities is an organism.  An individual slime mold cell is an organism as is a congrecgation of slime mold cells.  A sponge cell is an organism as is the sponge. When we think about something like the Portugese Man of War what do we do.  Is it an organism or a colony of organisms. We are getting into semantics.
 But that is just my definition.