CMLA Hematology Basics 2 — Questions and Answers
Question 1: Which white blood cell is the first to respond to a bacterial infection?
- Neutrophil (Correct answer)
- Eosinophil
- Basophil
- Lymphocyte
Correct answer: Neutrophil
Neutrophils are the first responders to bacterial infection due to their rapid migration and phagocytic ability.
Question 2: What is the normal lifespan of a red blood cell in circulation?
- 60 days
- 90 days
- 120 days (Correct answer)
- 150 days
Correct answer: 120 days
Red blood cells have a normal lifespan of approximately 120 days before being removed by the spleen.
Question 3: Which organelle is absent in mature red blood cells?
- Cell membrane
- Hemoglobin
- Nucleus (Correct answer)
- Cytoplasm
Correct answer: Nucleus
Mature red blood cells lack a nucleus, which was extruded during the final stages of erythropoiesis.
Question 4: The MCHC (Mean Corpuscular Hemoglobin Concentration) is calculated by dividing:
- Hemoglobin by RBC count
- Hemoglobin by hematocrit × 100 (Correct answer)
- MCV by MCH
- Hematocrit by RBC count
Correct answer: Hemoglobin by hematocrit × 100
MCHC is calculated as (Hemoglobin / Hematocrit) × 100, expressing average hemoglobin concentration per unit volume of red cells.
Question 5: A patient's blood smear shows target cells (codocytes). Which condition is MOST associated with this finding?
- Iron deficiency anemia
- Hemolytic anemia
- Hemoglobin C disease (Correct answer)
- Pernicious anemia
Correct answer: Hemoglobin C disease
Target cells are classically associated with hemoglobin C disease, thalassemia, and liver disease.
Question 6: Which test measures the ability of red blood cells to change shape under fluid stress?
- Osmotic fragility test (Correct answer)
- Red cell deformability test
- Coombs test
- Reticulocyte count
Correct answer: Osmotic fragility test
The osmotic fragility test measures RBC ability to withstand hypotonic solutions, reflecting membrane integrity and deformability.
Question 7: What is the primary function of 2,3-bisphosphoglycerate (2,3-BPG) in red blood cells?
- Provides energy for cell metabolism
- Stabilizes the hemoglobin molecule
- Decreases hemoglobin's affinity for oxygen (Correct answer)
- Maintains cell membrane integrity
Correct answer: Decreases hemoglobin's affinity for oxygen
2,3-BPG binds to deoxyhemoglobin and decreases its oxygen affinity, facilitating oxygen release to tissues.
CMLA Hematology Basics 2
Which white blood cell is the first to respond to a bacterial infection?