CMC Medical CMC-Medical VELLORE Solved Paper-2008

  • question_answer
    Which type of cells are absent in sponges?

    A)  Trophocytes    

    B)  Myocytes

    C)  Archeocytes    

    D)  Cnidocytes

    E)  All of these

    Correct Answer: D

    Solution :

                    Cnidocytes or stinging cells are found in entir epidermis except that of basal disc and are found only in cnidarians. These are spherical or oval cells, which possess a unique type of large and centrally located sac-like organelle called nematocyst. A basal nucleus, a small Golgi complex, scattered mitochondria, ribosomes endoplasmic reticulum and some fat globules are found in cytoplasm. Archaeocytes are undifferentiated totipotent cells, which may differentiate into all other types of cells. Myocytes are long and slender, highly contractile, spindle-shaped cells resembling unstriped muscle fibres. These form a circular sphincter around the osculum and serve to close or open it, as required. Trophocytes serve to supply nutrients to developing cells and hence, also called nurse cells.


You need to login to perform this action.
You will be redirected in 3 sec spinner