cell organisation

• specialised cells carry out particular functions
• the process by which cells become specialised for a particular job is called differentiation. differentiation occurs during development of multicellular organisms
• specialised cells form tissues, which form organs, which form organ systems.
• tissue - group of similar cells that work together to perform the same function
• large multicellular organisms have different systems inside them for exchanging and transporting materials
• in mammals what are some examples of tissues?

  • muscular tissue which contracts to move whatever it is attached to
  • glandular tissue, which makes and secretes chemicals like enzymes and hormones
  • epithelial tissue, which covers some parts of the body
• an organ is a group of different tissues that work together to perform a certain function
• organ system is a collection of organs working together to carry out a specific task
• examples of organ systems include respiratory system (lungs), digestive system (stomach) and circulatory system (heart)