organismsthat
Organismsthat is not a standard scientific term. It appears to be a concatenation of the words "organisms" and "that," and in ordinary writing it would usually be separated as two words: "organisms that." In a biological context, the phrase functions as a qualifier used to describe a group of organisms defined by a particular trait or criterion.
In practice, statements using this construction identify subgroups within larger categories. For example, "organisms that photosynthesize"
When writing about such groups, clarity depends on specifying the trait and the taxonomic scope. Phrases should