Blood GCSE
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Blood 12/05/22 03:15
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Blood GCSE standard
Transcript of Blood GCSE
10:45
Red blood cells
• Carry oxygen from lungs to body tissue.• There are 5 000 000 in 1mm3 of blood. • They are adapted in the following ways: (1) Size – thick diameter but thin width. They
just fit through a capillary but the surface to volume ratio is large so they can absorb a lot of oxygen.
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Red blood cells
(2) Shape – they are concave discs – this give greater surface area.
(3) No nucleus – leaves more room for haemoglobin – also no mitochondria or ribosomes.
(4) Haemoglobin – this is a protein that carries oxygen becoming oxyhaemoglobin.
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White blood cells
• Defend against diseases.• They ingest bacteria and viruses.• They produce antibodies.
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Human blood under microscope
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Platelets
• Platelets are small cells that allow blood to clot.
• This stops bleeding and prevent bacteria from entering the body.
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Plasma
• This is the straw coloured liquid in the blood.• Over 90% of plasma is water.• This dissolves: (1) food – amino acids and glucose (2) cholesterol – from the liver (3) hormones – from glands (4) antibodies (5) water – to kidneys (6) waste products like carbon dioxide and lactic acid
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Plasma
