Telomerase in Proliferating Lymphocytes

Steps:

• Telomerase enzyme adds telomere repeats to chromosome ends, enabling sustained cell division.
• Identify cell types: Neutrophils are terminally differentiated granulocytes with limited lifespan.
• Mature red blood cells are anucleate and incapable of any replication.
• Mature T-lymphocytes undergo activation and clonal expansion through multiple mitoses.

Why D is correct:

• Activated T-lymphocytes express high telomerase levels to counteract telomere erosion during immune response proliferation, per telomere biology principles.

Why the others are wrong:

• A: Neutrophils and red blood cells do not divide post-maturation, lacking telomerase.
• B: Neutrophils are post-mitotic and do not require telomerase for division.
• C: Neutrophils have low telomerase as they do not proliferate.

Final answer: D