What is the most immature cell in the granulocyte series?

What is the most immature cell in the granulocyte series?

• A. Megakaryoblast
• B. Myeloblast
• C. Leukoblast
• D. Progranuloblast

Answer: (B)

Granulocyte development begins with the myeloblast, the earliest recognizable precursor in this lineage. It has a large, round nucleus with fine chromatin and prominent nucleoli, and its cytoplasm contains almost no granules. As maturation proceeds, granulocytes acquire cytoplasmic granules (promyelocyte stage) and gradually compress and mature into band cells and finally fully mature granulocytes (neutrophils, eosinophils, basophils). Because a myeloblast is the initial, undifferentiated stage in this series, it is the most immature granulocytic cell. The other options belong to different lineages or are not standard primitive granulocytic stages, so they don’t fit the sequence.

Granulocyte development begins with the myeloblast, the earliest recognizable precursor in this lineage. It has a large, round nucleus with fine chromatin and prominent nucleoli, and its cytoplasm contains almost no granules. As maturation proceeds, granulocytes acquire cytoplasmic granules (promyelocyte stage) and gradually compress and mature into band cells and finally fully mature granulocytes (neutrophils, eosinophils, basophils). Because a myeloblast is the initial, undifferentiated stage in this series, it is the most immature granulocytic cell. The other options belong to different lineages or are not standard primitive granulocytic stages, so they don’t fit the sequence.