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Transport in humans
Higher
2 marks
Explain how the structure of red blood cells makes them efficient at carrying oxygen.
A
Biconcave shape (large SA:V); no nucleus (more haemoglobin); thin/flexible; packed with haemoglobin for O₂ binding
B
Large nucleus controls O₂ uptake; oval shape reduces resistance
C
They are large cells with many mitochondria to power O₂ transport
D
Square shape to pack efficiently in blood vessels
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Transport in humans — Biology (4BI1) | Smartzi