[KenGee (Kenith Gee)]

Mules can reproduce sometimes. Mules in general can't reproduce due to genetic abnormality, But that should not make them not alive would we call a human who can't have kids dead!
If you take it to another level all multicellular life can be seen as simply a well organised colony of single cell life!!!
As for the definition of life then I think we should simply make it this.
Any multi-element chemical that is capable of making a copy of it’s self.