so they have lot of space to carry oxygen.
Erythrocytes in mammals are anucleate when mature, meaning that they lack a cell nucleus and thus have no DNA. In comparison, the erythrocytes of nearly all other vertebrates have nuclei; the only known exception is salamanders of the Batrachoseps genus.[1]} Mammalian erythrocytes also lose their other organelles including their mitochondria and produce energy by fermentation, via glycolysis of glucose followed by lactic acid production. Furthermore, red cells do not have an insulin receptor and thus glucose uptake is not regulated by insulin. As a result of the lack of nucleus and organelles, the cells cannot produce new structural or repair proteins or enzymes and their lifespan is limited.
Mammalian erythrocytes are biconcave disks: flattened and depressed in the center, with a dumbbell-shaped cross section. This shape (as well as the loss of organelles and nucleus) optimizes the cell for the exchange of oxygen with its surroundings
2007-07-28 15:48:44
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answer #1
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answered by Oshi 3
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The thing is, they don't have DNA! Red blood cells are weird cells. They are not typical cells, because of their specific purpose for carrying oxygen and whatnot. They are stripped down cells that have had a lot of important parts removed. They do NOT have a nucleus, and are missing various other organelles as well. As a result, the do NOT have DNA (and cannot therefore make RNA either). Young red blood cells do actually contain nuclei (and therefore DNA), but they lose this as they mature (so that they can transport more hemoglobin and oxygen). They also lose other important organelles, like mitochondria and other stuff too. As a result, mature red blood cells have limited capabilities... like they can't divide and multiply, can't metabolize very much, can't repair themselves, etc. But this doesn't really matter, because your body makes large amounts of them all the time, and they don't need this stuff to carry oxygen. They are very specialized cells. The red blood cells of most mammals do not contain nuclei, actually. DNA can still be extracted from blood however, because blood contains many substances including other cells types, and these will contain nuclei and DNA like all normal cells. So there you go!! Hope that helps you out! :) :)
2016-05-21 05:34:56
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answer #2
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answered by ? 2
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the concave shape increases their surface area, which works great while absorbing oxygen.
2007-08-01 14:35:53
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answer #3
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answered by bad guppy 5
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cellular division
2007-07-28 15:51:15
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answer #4
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answered by Anonymous
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