why do human red blood cells lack nucei?

Answer 1

To make more room for haemoglobin so more oxygen can be transported.

Answer 2

I'm not sure there is a decent answer to that question just yet. Mammals are the only vertebrates with red blood cells that lack nuclei. In other vertebrates a nuclei is present and the cells are much larger. Decreasing the size of the cell results in a greater surface area to volume ratio whcih would mean the cells can take up oxygen and dump CO2 more quickly. This is probably beneficial in mammals due to their higher metabolism. The nuclei were likely lost because they would have filled the smaller cells. However, as noted above, birds also have nuclei in their red blood cells and birds have a very high metabolism rate as well (they are endothermic like mammals). The disadvatages of the nuclei may be offset by the fact that the respiratory system of birds is far more efficient than ours. The lack of nuclei in our red blood cells is likely a fotuitous accident (as is usually the case in biology).

Answer 3

A nucleus would make the red blood cell not compliant enough (it would not be as easily capable of going into very small blood vessels) and the DNA weight would take away from the oxygen carrying capacity. A good thing it is actually, otherwise, any blood transfusion would require the same kind of anti-reject drugs as are needed with organ transplant.

Answer 4

Another important reason is:

Blood cells don't need to go through cell division to make more blood cells. Blood cells are made from bone marrow.

So since no need for cell division, they don't really need nuclei.

Answer 5

The flattened shape and the abscence of a nucleus optimizes the oxygen carrying capacity of the cell... which is the RBC's job.

Answer 6

because a nucleus is not needed. All redblood cells do is carry oxygen and release it. It does this through diffusion and this occurs naturally without something making it do it, and it also takes up too much space, more space is need to to cary more oxygen

Answer 7

Nucleus and coloration. Nucleus because of the fact they're purely transport contraptions that's why they have that doughnut shape (as somebody else stated) and coloration because of the fact the purple turns to blue whilst oxygen is bumped off and CO2 is it incredibly is alternative (it gets its coloration from the linked molecule related to it.) It has a cellular membrane, and it has fluid (plasma, i believe... incredibly i'm completely incorrect yet i comprehend it has something.)

Answer 8

An interesting question is why birds have nuclei in their redblood cells.

Answer 9

As they mature, the organelles dissolve.