3.5 cell specialisation and organisation

• epithelial tissues line the surface of organs and often have protective or secretory functions
• xylem is a tissue in plants that is used to transport water and mineral ions throughout the plant
• the stomach is made up of:

  1. muscle to churn and mix stomach contents
  2. epithelium to protect the stomach wall and produce secretions
  3. connective tissues to hold other tissues together
• a plant leaf is an organ
• the leaf is made out of:

  1. palisade mesophyll which contains palisade cells that carry out photosynthesis
  2. spongy mesophyll adapted for gaseous diffusion
  3. epidermis to protect the leaf and allow gaseous diffusion
  4. phloem to transport organic materials away from the leaf
  5. xylem to transport water and ions into the leaf
• the digestive system digests and processes food
• the respiratory system is used for breathing and gas exchange
• the circulatory system pumps and circulates blood