2007-03-13 14:56:52 · 4 answers · asked by kayeh 1 in Science & Mathematics ➔ Zoology
Red blood cells are produced in the red bone marrow and spleen from a stem cell called a hemopoietic cell. It starts off with a nucleus, but during the course of development into a red blood cell, it ejects its nucleus. What we see under a microscope as "an incomplete hole" is really just a thinner part of the cell where the nucleus used to be. The light shines brighter here.
ANATOMY AND PHYSIOLOGY TEACHER
2007-03-13 17:23:09 · answer #1 · answered by CAROL P 4 · 0⤊ 0⤋
As wild speculation: to maximize surface area while minimizing hydrodynamic drag and potential for damage during transport. A hole would dramatically increase drag (i think?) and compexity (of cell wall) with little (or none) benefit to O2 exchange. A more irregular shape would be a huge drag in blood stream. Alternative answer: Why not? Alternative answer three: I'm not sure you can answer this question - you can give the benefits and the costs, but to answer "why" would require solid evidence for the reasons the mutations were chosen - and we weren't there!
2007-03-13 22:08:06 · answer #2 · answered by Anonymous · 1⤊ 0⤋
Mammalian RBC is oval or doughnut. It is because;
1. to increase surface of absorption for O2(oxygen).
2.Nucleus are absent in them, they die after 120 days.
2007-03-15 08:59:19 · answer #3 · answered by sagar k 1 · 0⤊ 0⤋
Because it has no nucleus and the shape maximizes area to volume when starting with a sphere.
2007-03-13 22:12:21 · answer #4 · answered by Mike1942f 7 · 1⤊ 0⤋