Biology Exchange and Transport

Exchange Surfaces

• Surface Area to Volume Ratio: The ratio of the surface area of an organism to its volume. A higher ratio allows for more efficient exchange of substances.
• Types of Exchange Surfaces:
  • Alveoli (lungs): gas exchange between air and blood
  • Villi (small intestine): absorption of nutrients into bloodstream
  • Root hair cells (plants): absorption of water and minerals from soil

Transport in Animals

• Blood Circulatory System:
  • Functions:
    • Transport of oxygen and nutrients to cells
    • Transport of carbon dioxide and waste products away from cells
  • Components:
    • Heart: pumps blood throughout the body
    • Arteries: transport oxygenated blood away from heart
    • Veins: transport deoxygenated blood towards heart
    • Capillaries: site of exchange between blood and tissues
• Blood Components:
  • Plasma: liquid portion of blood, carrying proteins, nutrients, and waste products
  • Red Blood Cells (RBCs): carry oxygen from lungs to tissues
  • White Blood Cells (WBCs): part of immune system, fighting infection
  • Platelets: involved in blood clotting

Transport in Plants

• Xylem:
  • Functions:
    • Transport of water and minerals from roots to leaves
    • Transport of sugars produced in photosynthesis to rest of plant
  • Components:
    • Tracheids: dead, hollow cells that form xylem vessels
    • Vessel elements: living cells that form xylem vessels
• Phloem:
  • Functions:
    • Transport of sugars produced in photosynthesis to rest of plant
    • Transport of hormones and other organic compounds
  • Components:
    • Sieve cells: living cells that form phloem vessels
    • Companion cells: living cells that support sieve cells