Transport in animals

• Erythrocytes:

  • biconcave shape- provides a larger surface area for diffusion of gases
  • No nuclei- maximises amount of haemoglobin that fits into the cells and limits their life
• Health = mental and physical well-being
• Cartilage is essential to the trachea as:

  • it provides strength and support to keep it open
  • it provides support to prevent collapse during inspiration