In a hypertonic (low external Q) environment, the cell loses water and
   plasmolyzes.  Video:  <A ClAsS=MID Href="../../../med/Vid/Campbell7e/Plasmolysis-V.swf" oNClick="popurlt('../../../../med/Vid/Campbell7e/Plasmolysis-V.swf');txtcolor('water_plants1','gray');return false;" Id=water_plants1><iMg sRc="/images/shockwave.gif" aLt='' boRDer=0></A>  In  a  hypotonic  (high external Q) environment,
   there is net uptake of water by osmosis, the cell becomes turgid which
   helps it retain its shape.