Plasma:
- Liquid part of the blood
- Carries the blood cells through the blood vessels
- Contains many dissolved substances such as carbon dioxide and glucose
White blood cells:
- Larger than red blood cells
- Have a nucleus
- Some surround and destroy pathogens
- Some produce antibodies that destroy pathogens
Platelets:
- Are fragments of larger cells
- Have no nucleus
- Causes blood to clot when a blood vessel has been damaged
Red blood cell:
- Contains haemoglobin which carries oxygen
- Has a biconcave shape which gives it a larger surface area
- Oxygen diffuses in and out of the cell
- Has no nucleus to give the cell more room for more haemoglobin to carry more oxygen