what happens if you leave an elodea leaf in glucosefor several hours?

Answer 1

Plasmolysis.

The glucose solution is hypertonic for the elodea cells. More water diffuses out of the cells than the amount of water that diffuses into the cells. The cytoplasm shrinks, and the plasma membrane pulls away from the cell wall. See a picture here of the end result. http://images.search.yahoo.com/search/images;_ylt=A0geu8YmlWhHC3EAgbpXNyoA?ei=UTF-8&p=elodea%20plasmolysis&fr2=tab-web&fr=ks-ans