Question

Assertion
RBC production is regulated by kidneys.
Reason
Erythropoietin hormone produced by kidneys reaches the red bone marrow where it increases stem cells mitosis and speeds up development of RBCs.
A)Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
B)Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
C)Assertion is correct but Reason is incorrect
D)Both Assertion and Reason are incorrect

Answer 1

In reaction to low oxygen levels, erythropoietin is developed in the kidney and liver. In addition, erythropoietin is bound by red blood cells that circulate; low circulating numbers contribute to a relatively high level of unbound erythropoietin that activates bone marrow production.

Complete answer:
The regulation of RBC production is accompanied by the hormone erythropoietin, which is secreted by the juxtaglomerular cells of the kidney. This hormone circulates to the red bone marrow, where it increases stem cell mitosis and speeds the development of RBC.

This hormone stimulates the proliferation and differentiation of red cell precursors, which induces increased erythropoiesis in the hemopoietic tissue, eventually generating red blood cells (erythrocytes). This hormone stimulates the proliferation and differentiation of red cell precursors, which activates increased erythropoiesis in the hemopoietic tissues, ultimately producing red blood cells (erythrocytes). Erythropoiesis passes to the liver in the third or fourth month. Erythropoiesis happens in the bone marrow after seven months. A rise in erythropoiesis may induce an elevated degree of physical activity. However, erythropoiesis often happens outside the bone marrow, within the spleen or liver in persons with some diseases and in certain animals. This is known as erythropoiesis, extramedullary.

Hence, the correct answer is option (A)

Note: Red blood cells are produced by the bone marrow of virtually all the bones before a person is about five years old. At around age 25, the tibia and femur cease to be major sources of hematopoiesis; red blood cells continue to produce vertebrae, sternum, pelvis and ribs, and cranial bones during life.