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Biology
Differentiation
All multicellular organisms have stem cells
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These divide by mitosis and undergo process of differentiation
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Stem cells can also divide to produce more stem cells
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Their main function is to transport oxygen around the body
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Erythrocytes are formed from stem cells in bone marrow
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So new cells have to be constantly formed from stem cells in order to
maintain the erythrocytes count in the blood
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Stages of erythropoiesis:

Stem cells of the bone marrow are Multipotent – they are capable of
forming a number of different types of body cells
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Haemoglobin , oxygen-carrying pigment of red blood cell accumulates in
the cytoplasm, than after the nucleus is ejected from the cell
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It has to
undergo further change
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Structure and function in erythrocytes:
Differentiation involves changes that adapt the structure of the cell to its
function
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this shape has greater surface area ,
due to the double indentation
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- Cytoplasm contains lots of haemoglobin, (280 million molecules)
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g
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Allows more haemoglobin to be packed
into cytoplasm
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- An elastic membrane allows the red blood cell to change shape, allows it
to squeezes through the narrow capillaries

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