question_answer 41)

  Structural organization  in  animals  attains  different levels  as cell-organ-organ system. What is missing in this chain? Mention the significance of such an organization.

Answer:

                  Tissue is the missing in the chain. Structural organization can be shown as cell-tissue-organ-organ system.             Number of cells together form tissue, number of tissue together form organ which on whenunit with several organ form organ-system. In organisms like Hydra, the body is comprised of thousands of cells in which each cell works independently whereas in a complex body system as that in humans billions of cells perform various functions together v/'a connecting each other through connecting tissue.