Blood

• What components make up blood?

  1. Plasma
  2. Red blood cells
  3. White blood cells
  4. Platelets
• What is the function of plasma in blood?

  • Carries blood components
  • Transports glucose, amino acids, hormones, and waste products
• What are the functions of red blood cells?

  • Carry oxygen from lungs to cells
  • Bioconcave shape for large surface area
  • No nucleus for more oxygen capacity
  • Contain haemoglobin for oxygen binding
• What is the role of white blood cells?

  • Part of the immune system
  • Defend against pathogens
  • Types include antibody producers, engulfers, and antitoxin producers
• What is the function of platelets in blood?

  • Help form blood clots at wound sites
  • small fragments of cells
  • no nucleus
  • Prevent excessive bleeding and bruising
• Name adaptations of red blood cells


  • They have no nucleus - they lose it during their development - so they can pack in more haemoglobin.
  • They are small and flexible so that they can fit through narrow blood capillaries.
  • They have a biconcave shape - they are the shape of a disc that is curved inwards on both sides - to maximise their surface area for oxygen absorption.
  • They are thin, so there is only a short distance for the oxygen to diffuse to reach the centre of the cell.