When does a Erythrocyte (red blood cell) ever have a nucleus, and why is it usually an anucleate?
99501
>>>>When does a Erythrocyte (red blood cell) ever have a\n>>>> nucleus\n\nImmature mammalian RBCs have anucleus. The RBCs of most non-mammalian vertebrates retain their nuclei.\n\n>>>>>and why is it usually an anucleate?\n\nIncreased surface areas relative to volume. That allows a larger surface for the diffusion of gases.
497817
they do have a nucleus when they are still being formed in the red bone marrow, but once they are mature enough the nucleus is excluded so that there is maximum room to store-hole hemoglobin in the rbc.  less than 1% of rbcs are found in the cirulation-blood.  If more than that,it is indicative of disease and needs to be treated since rbcs with nucleii can't carry oxygen, are too big,and get squished-damaged in the capillaries.  Without a nucleus they can fit single file and go thru without getting too beat up-bruised and live their usual life of 120 days.
407930
Red Blood Cells have an average life span of 120 days.\n\nsorry that I couldn't find more... but I hope that helps at least a small bit...
546092
Red blood cells are the most common type of blood cell and are the vertebrate body's principal means of delivering oxygen from the lungs or gills to body tissues via the blood.\n\nRed blood cells are also known as RBCs or erythrocytes (from Greek erythros for "red" and kytos for "hollow", with cyte nowadays translated as "cell"). A schistocyte is a red blood cell undergoing fragmentation, or a fragmented part of a red blood cell.\n\n\nThe diameter of a typical human erythrocyte disk is 6–8 µm; they are thus much smaller than most other human cells. A typical erythrocyte contains about 270 million hemoglobin molecules, with each carrying four heme groups.\n\nAdult humans have roughly 2–3 × 1013 red blood cells at any given time (women have about 4 million to 5 million erythrocytes per cubic millimeter (microliter) of blood and men about 5 million to 6 million; people living at high altitudes with low oxygen tension will have more). Red blood cells are thus much more common than the other blood particles: There are about 4,000–11,000 white blood cells and about 150,000–400,000 platelets in a cubic millimeter of human blood. The red blood cells store collectively about 3.5 grams of iron; that's more than five times the iron stored by all the other tissues combined.\n\nThe process by which red blood cells are produced is called erythropoiesis. Erythrocytes are continuously being produced in the red bone marrow of large bones. (In the embryo, the liver is the main site of red blood cell production.) The production can be stimulated by the hormone erythropoietin (EPO), which is used for doping in sports. Erythrocytes develop in about 7 days and live a total of about 120 days. The aging cells swell up to a sphere-like shape and are engulfed by phagocytes, destroyed and their materials are released into the blood. The main sites of destruction are the liver and the spleen. The heme constituent of hemoglobin is eventually excreted as bilirubin.\n\nThe blood types of humans are due to variations in surface glycoproteins of erythrocytes.\n\nRed blood cells can be separated from blood plasma by centrifugation. During plasma donation, the red blood cells are pumped back into the body right away, and the plasma is collected. Some athletes have tried to improve their performance by doping their blood: First about 1 liter of their blood is extracted, then the red blood cells are isolated, frozen and stored, to be reinjected shortly before the competition. (Red blood cells can be conserved for 5 weeks at −78 °C.) This practice is hard to detect but may endanger the human cardiovascular system which is not equipped to deal with blood of the resulting higher viscosity\n\n\nDiseases and diagnostic tools\n \nAffected by Sickle-cell disease, red blood cells alter shape and threaten to damage internal organs.Blood diseases involving the red blood cells include:\n\nAnemias (or anaemias) are diseases characterized by low oxygen transport capacity of the blood, because of low red cell count or some abnormality of the red blood cells or the hemoglobin. \nIron deficiency anemia is the most common anemia; it occurs when the dietary intake or absorption of iron is insufficient, and hemoglobin, which contains iron, cannot be formed \nSickle-cell disease is a genetic disease that results in abnormal hemoglobin molecules. When these release their oxygen load in the tissues, they become insoluble, leading to mis-shaped red blood cells. These sickle shaped red cells are rigid and cause blood vessel blockage, pain, strokes, and other tissue damage. Specifically, Sickle-cell disease is due to a mutation of the Glu-6 residue to Val-6 on the outside of the hemoglobin protein; this change from a polar, charged amino acid to a hydrophobic amino acid causes the structural change seen in Sickle red blood cells. \nThalassemia is a genetic disease that results in the production of an abnormal ratio of hemoglobin subunits
134260
Without a nucleus there is more room for haemoglobin and therefore a greater oxygen-carrying capacity.\nThe consequence is that red blood cells have a short life span; they are constantly being broken down and the parts recycled (except the haem bit which is got rid of into the gut).\nSince the red blood cells have a short life span they must continually be replaced. You can see the importance of a good supply of iron in our diet.\nYou might like to ponder over the diet of new-born mammals - there is no iron in milk.
285214
In the nucleus, except in preparation for cell division.  Eukaryotes are defined by the presence of a nucleus, with "eukaryote" being greek for "True Nut."  A prokaryotic cell lacks a nucleus.\n\nDNA remains in the nucleus, and RNAs act as messenger molecules to transfer information out for protein synthesis.
870430
Whole blood contains R.B.C the red blood corpuscles. Plasma is devoid of red cells.
540881
One single drop of blood contains around a million erythrocytes, or Red Blood Cells \n and FYI, the average life span of a Red blood cell is 120 days!!!
321540
An erythrocyte ( red blood cell ) is about 7 MICROMETRES in diameter i.e. 0.000 007 m   -->  7x10^-6 m\n\nPLEASE NOTE nanometres are a billionth of a metre i.e. a thousandth of a micrometre!!\n\nAn atom is about 0.2nm in diameter - the haemoglobin molecule itself is made of hundreds of atoms, and there are about 250,000 haemoglobin molecules in an erythrocyte!!\n\nNO CELL IS SMALLER THAN ABOUT 0.5 micrometre!!!
145375
Red blood cells are also known as RBCs or erythrocytes (from Greek erythros for "red" and kytos for "hollow", with cyte nowadays translated as "cell").
527410
Red blood cells or Rbc are produced in your red bone marrow of your sternum, your chest bone. They have a lifespan of about 120 days. Then as then get old, these blood cells enter the spleen (also called the red splenic pulp) where it is forced through small pores. So that causes the rbc to be broken down physically. Then the hemoglobin in RBc is transferred to the liver by combining with a protein called haptaglobin an the hemoglobin is furthur broken down.\n\nThe protein in the RBC (alpha and beta chains) are broken down in the liver into amino acids. Iron in the hemoglobin is also either stored or reused by the liver.
288253
mammals have nucleated rbc`s when the rbcs are in teir young state
543591
in a way, i think this doc is right...blood without red blood cells, which is the majority of the formed elements in the blood contents, is plasma. what makes up blood plasma is water, electrolytes (salt), plasma protein. what makes up tears is water, salt, enzyme (a form of protein). so i think Dr. Karl makes sense in this way....but, besides RBCs, there are WBCs, and platelets in blood...so he had said...tears are blood without formed elements, he could have been more precise...
801058
Nucleated red cells in an adult human are very immature forms that can be released into the blood stream at time of stress like severe anemia. \nNucleated red cells are NORMAL in the unborn or recently born.\nTotal leukocyte count refers to the number of White Blood Cells usually reported in thousands per cubic millimeter. If the number is elevated (like 30-50 thousand) in the presence of nucleated red cells can be a sign of Leukemia, a cancer of the blood forming cells.
935984
For eukaryotes, in the neucleus. For prokaryotes, the cytoplasm because they don't have a nucleus.
92432
The prokaryote cell does not contain a nucleus. Prokaryote cells are only one celled organisms.\nEukaryote cells can be of one celled organisms, or multi-celled (like you and me). Eukaryote cells contain mitocondria, I don't beleave prokaryotes do.
277238
an organism composed of one or more cells containing visibly evident nuclei and organelles