The presence of the vacuole is a very conspicuous feature of mature plant cells. They occur in cytoplasmic matrix of the cell starting off as a few small vacuoles in young plant cells. These vacuoles grow and merge as the cell matures. Vacuoles are seldom prominent features in animal cells and are normally confined to simple animal forms where they are observed as small contractile vacuoles.


In plant cells vacuoles may occupy 80% or more of the volume of the cell. The cytoplasm and nucleus are compressed against the cell wall. Vacuoles are cavities in the cytoplasm (especially in plant cells) surrounded by a cytoplasmic membrane, the tonoplast, and filled with a watery fluid called the cell sap.


An illustration of a


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