CIE IGCSE Biology: 复习笔记：9.1.14 Components of Blood

• Blood consists of red blood cells, white blood cells, platelets and plasma

Composition of human blood

Components of the Blood Table

• You need to be able to identify red and white blood cells in photomicrographs and diagrams
  • Red blood cells have a concave disc shape with no nucleus
  • White blood cells are usually round in shape with a nucleus

Blood micrograph

• Plasma is important for the transport of carbon dioxide, digested food (nutrients), urea, mineral ions, hormones and heat energy
• Red blood cells transport oxygen around the body from the lungs to cells which require it for aerobic respiration
  • They carry the oxygen in the form of oxyhaemoglobin
• White blood cells defend the body against infection by pathogens by carrying out phagocytosis and antibody production
• Platelets are involved in helping the blood to clot

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