Erythropoiesis starts in:

Explanation

Erythropoiesis is the formation of red blood cells (erythrocytes) which occurs in the red bone arrow. Proerythroblast is the earliest precursor which gives rise successively to the early erythroblast, intermediate erythroblast and late erythroblast. Then, the nucleus is forced out and a biconcave, enucleated cell called reticulocyte is formed, which is released into blood. In blood, it develops into mature erythrocytes. Red bone marrow, found in certain bones of the body, is the primary site for erythropoiesis. It is responsible for producing red blood cells (erythrocytes), along with other blood cell types like white blood cells and platelets. Red bone marrow contains stem cells known as hematopoietic stem cells that give rise to various blood cell lineages, including red blood cells.