Insects

• Insect transport system?

  Insects do no carry oxygen in blood, they have an open circulatory system which means the body fluid can act as both blood and tissue fluid.
• Tracheal system structure?

  It is an air filled system and air enters the system via a pore in each segment called a spiracle. The air is transported through a series of tubes called tracheae which then divide into smaller tubes called tracheoles. The tracheoles are open at the end and have tracheal fluid at the ends. Gaseous exchange occurs between the air in the tracheoles and the tracheal fluid. Exchange can also occur through the thin walls of the tracheoles
• Active and resting tissue?

  Active insects need a good supply of oxygen so tracheal fluid can be withdrawn to allow there to be a larger surface area for exchange. Resting tissues have more tracheal fluid in the tracheoles