A biological process is a recognized series of events or molecular functions. A process is a collection of molecular events with a defined beginning and end. Mutant phenotypes often reflect disruptions in biological processes.
Beginning and end
Every process should have a discrete beginning and end, and these should be clearly stated in the process term definition.
Collections of processes
The biological process ontology includes terms that represent collections of processes as well as terms that represent a specific, entire process. Generally, the former will have mainly is_a children, and the latter will have part_of children that represent subprocesses. Also see "is_a or part_of" below.
is_a or part_of
To determine whether a process term should be an is a or part of child of its parent, ask: is an instance of the child process an instance of the entire parent process? That is, does the whole process, from start to finish, take place? If yes, the child is is a; but if the process is only a portion of the parent process, the child is part of.