Polycythemia or an increase in red blood cells
The number of RBC will increase
If your bone marrow is producing an elevated number of red blood cells, your hematocrit (percentage of red blood cells in the blood) will increase. This can be a sign of conditions such as polycythemia vera or dehydration. High hematocrit levels can increase blood viscosity and strain the heart.
the hormone that produces red blood cells is erythropoeitin.
It loses oxygen!
this mostly happens with multi-cellular organisms and red blood cells. Red blood cells lose their nucleus.
Erythropoiesis (making red blood cells) and the synthesis of other blood cells.
Iron.
The medical term is erythropoietin, which is a hormone produced by the kidney to stimulate the production of red blood cells in the bone marrow.
The number of red blood cells will increase but they will be proportional to the body size. In a way you can say that nothing will change. The numbers grow Just as the numbers of bone and muscle cells grow along with the increasing growth in body size.
Red blood cells are made by the marrow.
They are broken down in the liver.