In  plants,  chloroplasts  are  found
   mainly in the mesophyll cells of a leaf.
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   The  stomata are openings in the leaf that allow gas exchange with the
   atmosphere.
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   Leaf structure review:  <A ClAsS=ACT Href="http://media.pearsoncmg.com/bc/bc_campbell_biology_7/media/activities/load.html?10&amp;A" oNClick="popact('http://media.pearsoncmg.com/bc/bc_campbell_biology_7/media/activities/load.html?10&amp;A');txtcolor('chloroplast2','gray');return false;" Id=chloroplast2><iMg sRc="/images/tutorial.gif" aLt='' boRDer=0></A>