This refers to chemical reactions involved in maintaining the living state of the cells and organisms. 

    Types of Metabolism

  *Anabolism--This is the synthesis of materials needed to maintain the cells of the body.

  *Catabolism-- This is the breakdown of molecules to obtain energy.

    A system through which food, oxygen, hormones are carried to their target organs and also waste metabollic materials are removed is termed transport or circulatory system.

        Importance of Transport Systen

 *Regulation of body temperature through distribution and transportation of heat.

 *Regulation of water balance in the body.

 *Through transport systems, hormones in animals and auxins in plants are carried to their target tissues.

 *Transports excess useful substances to specialised tissues that can store them.