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→Adaptations of Villi
===Adaptations of Villi===
: [[Villi]] have a wall only one cell thick so the [[nutrient]]s only have a short distance to [[Diffusion|diffuse]] into the [[blood]].
: [[Villi]] have [[Capillary|capillaries]] in order to constantly supply enough fresh [[blood]] with few [[nutrients]] keeping a high [[Concentration Gradient|concentration gradient]] between the food and the [[blood]].
: [[Villi]] have a large [[Surface Area|surface area]] to allow quicker [[diffusion]].
:[https://www.amazon.co.uk/gp/product/1782945954/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945954&linkCode=as2&tag=nrjc-21&linkId=100574c08fbbb64318256eb79ed61a76 ''Villi, page 65, GCSE Biology, CGP, AQA '']
:[https://www.amazon.co.uk/gp/product/0198359373/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=0198359373&linkCode=as2&tag=nrjc-21&linkId=952a73bbb09d222ecc4b50d200679849 ''Villi, pages 15, 23, 39, GCSE Biology; Third Edition, Oxford University Press, AQA '']
====OCR====
:[https://www.amazon.co.uk/gp/product/1782945660/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945660&linkCode=as2&tag=nrjc-21&linkId=83aa4500ad7759e7f401a1c5ba5df758 ''Villi, page 34, Gateway GCSE Biology; The Revision Guide, CGP, OCR '']
:[https://www.amazon.co.uk/gp/product/0198359810/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=0198359810&linkCode=as2&tag=nrjc-21&linkId=d768d99f1a06f7c12fab40e5aef85a55 ''Villi, pages 63, 73, Gateway GCSE Biology, Oxford, OCR '']