ICSE Class 10 Answered

1. Red blood cells carry oxygen to the tissues.

2. Platelets help prevent bleeding and aid in clotting of blood.

The relation between bone marrow and RBCs is that red blood cell production takes place in the bone marrow under the control of the hormone, erythropoietin (EPO). This process is called erythropoiesis.

Within the bone marrow, all blood cells originate from a single type of unspecialized cell called a stem cell. When a stem cell divides, it first becomes an immature red blood cell. The immature cell then divides, matures further, and ultimately becomes a mature red blood cell.