Adaptations of effective exchange surfaces in all organisms

• What is the human respiratory system adapted for?

  Efficient gas exchange
• What are the levels of organization in multicellular organisms?

  • Cells
  • Tissues
  • Organs
  • Systems
• What increases the effectiveness of exchange surfaces in plants and animals?

  A large surface area and a short distance for diffusion
• What is the flattened shape of structures such as leaves and alveoli beneficial for?

  It provides a large surface area for gas exchange
• What are alveoli?

  Tiny air sacs in the lungs where gas is exchanged
• What are villi?

  Finger-like projections in the small intestine that absorb food
• Why are the walls of blood capillaries one cell thick?

  To facilitate the exchange of materials
• What is the role of epithelial cells in exchange surfaces?

  They form part of the epithelium
• How do large, flat leaves enhance gas exchange?

  By providing an effective exchange surface
• What is the benefit of an efficient blood supply to exchange surfaces?

  It transports molecules to and from the exchange surface
• What surrounds each alveolus in the lungs?

  A network of blood capillaries
• What is the process of breathing also known as?

  Ventilation
• How does breathing affect gas exchange in the alveoli?

  It brings air to and removes air from the exchange surface
• What does a steep concentration gradient facilitate?

  It increases effective exchange
• What adaptations do animals have for effective exchange surfaces?

  • A large surface area
  • A short distance for diffusion
  • An efficient blood supply
• What are the key features of effective exchange surfaces?

  • Large surface area
  • Thin membranes (one cell thick)
  • Efficient blood supply
  • Ventilation to maintain concentration gradients