Definition is a rhetorical mode that can be used in something smaller or shorter than a full paper. You can use extended definition for several paragraphs only in a paper of much greater length. You also can add to a paper a one-paragraph definition--like a brief encyclopedia definition.
The research group, headed by Dr. Lukas Sommer at the Swiss Federal Institute of Technology, has identified a heretofore unknown role for the TGF cell-to-cell signaling pathway in the pathogenesis of DiGeorge syndrome.
Meniere's disease is associated with. A. loss of vestibular hair cells This answer is INCORRECT. Damage due to the loss of vestibular hair cells will impair vestibular function. However, the defining feature of Meniere's disease is swelling of the membranous labyrinth.