Differences on Sciences (was Science)
The Sciences division was the corps of officers and crewmen within Starfleet who specialized in both scientific and medical research and control functions on starbases, aboard starships, and at Starfleet Command.
Members of the Sciences division specialized in sensors, research, theoretical and physical laboratory work, biological studies, and also worked as technicians, medics, and surgeons. Officers within this division were mostly limited to scientific or medical assignments such as doctors, nurses, and scientists working in a variety of disciplines. These officers served as department heads such as chief medical officers and head science officers.
Opportunities for command assignments were somewhat limited for these officers due to their lack of overall command experience and training. However, officers who had taken and passed the Bridge Officer's Test could be promoted in rank to commander and were certified to command a starship, if necessary. In most instances, however, science division officers would only take command of a ship or starbase in the absence of other senior officers due to circumstances such as an emergency, illness of a commanding officer, or manpower shortages as may have occurred in wartime, for example.
Members of the sciences division belonged to such departments as astrometrics, astrophysics, astrosciences, geophysics, hydroponics, planetary geosciences, quantum mechanics, and stellar cartography.