Platelets are fragments of which cell type?

Platelets are fragments of which cell type?

• A. Megakaryocytes
• B. Lymphocytes
• C. Erythrocytes
• D. Osteoclasts

Answer: (A)

Platelets are fragments of megakaryocytes. In the bone marrow, megakaryocytes extend into blood vessels and shed small cytoplasmic pieces into circulation, producing platelets. These fragments lack a nucleus and contain granules that help initiate clotting to stop bleeding. The other cell types listed—lymphocytes, erythrocytes, and osteoclasts—do not give rise to platelets: lymphocytes are immune cells, erythrocytes are mature red blood cells, and osteoclasts are bone-resorbing cells.

Platelets are fragments of megakaryocytes. In the bone marrow, megakaryocytes extend into blood vessels and shed small cytoplasmic pieces into circulation, producing platelets. These fragments lack a nucleus and contain granules that help initiate clotting to stop bleeding. The other cell types listed—lymphocytes, erythrocytes, and osteoclasts—do not give rise to platelets: lymphocytes are immune cells, erythrocytes are mature red blood cells, and osteoclasts are bone-resorbing cells.