The blood

• What part of the human circulatory system does blood belong to?

  It is part of the human circulatory system.
• What are the two main components of blood?

  Blood vessels and the heart.
• What are the four components of blood?

  • 55% plasma
  • Red blood cells (45%)
  • White blood cells
  • Platelets
• What is plasma and what is its appearance?

  Plasma is a straw-colored liquid that makes up 55% of blood.
• What is the primary function of plasma in the blood?

  It transports red blood cells and chemicals around the body.
• What percentage of blood is made up of red blood cells?

  45%
• What is the main function of red blood cells?

  They carry oxygen to the body's cells.
• What pigment in red blood cells binds to oxygen?

  Haemoglobin.
• Why do red blood cells not have a nucleus?

  To provide more space for carrying oxygen.
• What is the shape of red blood cells and why is it beneficial?

  They are biconcave, which increases the surface area to volume ratio for carrying more oxygen.
• What are the two types of white blood cells mentioned?

  • White blood cells
  • Platelets
• What is the primary function of white blood cells?

  They protect the body against infection.
• How do white blood cells compare in size to red blood cells?

  They are larger than red blood cells.
• What are platelets?

  Fragments of cells.
• What is the primary function of platelets?

  They help stop blood clots and prevent bleeding.
• How do platelets help prevent bacteria from entering the body?

  They prevent bacteria from entering through wounds.
• How do platelets compare in size to red and white blood cells?

  They are smaller than red or white blood cells.