Depends.
On many things, no, but on anything the slightest bit controversial too many edits contradicting too many others.
For instance.
Most biology articles ( an article on oxidative phosphorylation, for instance ) are well written and written by experts.
An article on sociobiology has too many conflicting points of view, is constantly edited, ( unless locked ) and more ideologically inclined than scientifically descriptive.
Still, most teachers will not accept wiki articles are source material.