Brak jądra komórkowego w erytrocytch

Kto wie dlaczego w erytrocyctach nie ma jadra komórkowego?? Musze to wiedzieć!! POMOCY

:-)

A myslisz, ze nie szukałam?? Pisze tylko ze nie ma! I koniec =[ PLEASE

A na anglojęzycznych stronach też szukałaś? Bo myślę, że chyba nie :-)

No nie, nie szukałam. Aaa i zaraz lookne =)))p

Już znalazłem. Zajrzyj na stronę: http://www.madsci.org/posts/archives/2000-04/955119937.Cb.r.html Jest tam taka wypowiedź: "The reason that human (acutally all mammalian)mature red blood cells lack a nucleus appears to be so that the red blood cell has room for more hemoglobin and therefore can carry more oxygen per cell." Czyli dzięki braku jądra krwinka czerwona ma więcej miejsca na hemoglobinę i przez to może transportować więcej tlenu.

I jeszcze ze strony: http://www.science.edu.sg/ssc/detailed.jsp?artid=6140&type=6&root=4&parent=4&cat=48 Erythrocytes (or red blood cells) have nuclei throughout all stages of development except when they become mature cells. Then they discard their nuclei. This happens in the bone marrow, so you would not usually see the earlier stages in the peripheral blood. Once they lose their nuclei, they are not complete cells any more. They are just vessels. Red blood cells function by carrying oxygen to every part of the body, and then carrying carbon dioxide back to the lungs. Erythrocytes are very well designed to perform this important job. Each red blood cell is a biconcave disc. This shape greatly increases its surface area compared with a sphere of the same volume. The large surface area is important because it improves the efficiency of oxygen transfer between haemoglobin and the tissues where the oxygen is needed. The presence of a nucleus would change this shape. The lack of a nucleus allows greater cell deformity, so the disc can fold to fit through small capillaries that have a diameter slightly smaller than the erythrocyte. They do not need nuclei because they are not going to divide. So, for erythrocytes to have nuclei, it would be wasteful of resources, compromising to their functionality and potentially dangerous. Jak widać w Internecie można znaleźć wiele ciekawych rzeczy :-)