Question

Which one is another name of RBC?
A. Erythrocyte
B. Lymphocyte
C. Monocyte
D. Basophil

Answer 1

Hint: Blood has different types of cell. One of the blood cells is the red blood cell. The other name of this cell is erythrocyte. The cell is non-nucleated and biconcave in shape.

Step by step answer:Red blood cells, also called erythrocyte, cellular component of blood, millions of which in the circulation of vertebrates give the blood its characteristic colour and carry oxygen from the lungs to the tissues.
The mature human red blood cell is small, round, and biconcave; it appears dumbbell-shaped in profile. The cell is flexible and assumes a bell shape as it passes through extremely small blood vessels.
It is covered with a membrane composed of lipids and proteins, lacks a nucleus, and contains hemoglobin—a red iron-rich protein that binds oxygen.
The function of the red cell and its hemoglobin is to carry oxygen from the lungs or gills to all the body tissues and to carry carbon dioxide, a waste product of metabolism, to the lungs, where it is excreted.
In invertebrates, oxygen-carrying pigment is carried free in the plasma; its concentration in red cells in vertebrates, so that oxygen and carbon dioxide are exchanged as gases, is more efficient and represents an important evolutionary development.
The mammalian red cell is further adapted by lacking a nucleus—the amount of oxygen required by the cell for its own metabolism is thus very low, and most oxygen carried can be freed into the tissues.
The biconcave shape of the cell allows oxygen exchange at a constant rate over the largest possible area.
The red cell develops in bone marrow in several stages: from a hemocytoblast, a multipotential cell in the mesenchyme, it becomes an erythroblast (normoblast); during two to five days of development, the erythroblast gradually fills with hemoglobin, and its nucleus and mitochondria (particles in the cytoplasm that provide energy for the cell) disappear.
In a late stage the cell is called a reticulocyte, which ultimately becomes a fully mature red cell. The average red cell in humans lives 100–120 days; there are some 5.2 million red cells per cubic millimeter of blood in the adult human.
Though red cells are usually round, a small proportion is oval in the normal person, and in certain hereditary states, a higher proportion may be oval. Some diseases also display red cells of abnormal shape example - oval in pernicious anemia, crescent-shaped in sickle cell anemia, and with projections giving a thorny appearance in the hereditary disorder acanthocytosis.
The number of red cells and the amount of hemoglobin vary among different individuals and under different conditions; the number is higher, for example, in persons who live at high altitudes and in the disease polycythemia.
At birth the red cell count is high; it falls shortly after birth and gradually rises to the adult level at puberty. Erythrocytes are biconcave disks; that is, they are plump at their periphery and very thin in the center.
Since they lack most organelles, there is more interior space for the presence of the hemoglobin molecules that, as you will see shortly, transport gases.
The biconcave shape also provides a greater surface area across which gas exchange can occur, relative to its volume; a sphere of a similar diameter would have a lower surface area-to-volume ratio.
Hence option A is correct.

Note: The breakdown products are recycled or removed as wastes: globin is broken down into amino acids for synthesis of new proteins, iron is stored in the liver or spleen or used by the bone marrow for production of new erythrocytes, and the remnants of heme are converted into bilirubin, or other waste products that are taken up by the liver and excreted in the bile or removed by the kidneys. Anemia is a deficiency of RBCs or hemoglobin, whereas polycythemia is an excess of RBCs.