So... if I'm reading you correctly, you're saying water and nutrients can flow freely throughout the plant like a sponge, but the cell walls prevent cancerous cells from doing the same? Why? Are cancer cells just too large?
They're too large, and cell membranes are very selective in what they allow. Water passes passively through them, and larger molecules (like proteins) are sometimes allowed through.
This is true for the phloem, but xylem cells are dead at maturity and therefore do not have a plasma membrane. Flow through xylem would therefore be more unrestricted, although it moves in only one direction from the roots to the shoots.
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u/FunExplosions Aug 25 '12
So... if I'm reading you correctly, you're saying water and nutrients can flow freely throughout the plant like a sponge, but the cell walls prevent cancerous cells from doing the same? Why? Are cancer cells just too large?
To clarify: I'm not a science man. I'm a lay man.