Heamatology Practice Exam Answers
1. Which red blood cell indices are most useful in distinguishing microcytic anemias?
A) MCV
B) MCH
C) MCHC
D) RDW
✅ Correct Answer: A) MCV
Explanation: MCV (mean corpuscular volume) is the best indicator to classify anemias based on cell size. Microcytic anemias have decreased MCV.
Reference: Rodak BF, et al. Hematology: Clinical Principles and Applications, 5th ed.
2. Heinz bodies are composed of which of the following?
A) DNA
B) Iron
C) Denatured hemoglobin
D) RNA
✅ Correct Answer: C) Denatured hemoglobin
Explanation: Heinz bodies are aggregates of denatured hemoglobin seen in oxidative stress conditions and G6PD deficiency.
Reference: McKenzie SB. Clinical Laboratory Hematology, 3rd ed.
3. What is the most probable cause of a decreased ESR (erythrocyte sedimentation rate)?
A) Inflammation
B) High fibrinogen
C) Sickle cell anemia
D) Pregnancy
✅ Correct Answer: C) Sickle cell anemia
Explanation: Abnormally shaped red cells like sickle cells interfere with rouleaux formation, lowering ESR.
Reference: Henry’s Clinical Diagnosis and Management by Laboratory Methods, 23rd ed.
4. Which inclusion is typically seen in lead poisoning?
A) Howell-Jolly bodies
B) Heinz bodies
C) Pappenheimer bodies
D) Basophilic stippling
✅ Correct Answer: D) Basophilic stippling
Explanation: Basophilic stippling is due to precipitated RNA seen in lead poisoning and other toxic anemias.
Reference: Rodak BF, et al.
5. What is the most appropriate stain for detecting iron in bone marrow?
A) Wright-Giemsa
B) Sudan black B
C) Prussian blue
D) PAS
✅ Correct Answer: C) Prussian blue
Explanation: Prussian blue stain highlights iron stores (hemosiderin) in marrow macrophages.
Reference: McKenzie SB.
6. Which of the following cells is the earliest recognizable erythroid precursor?
A) Reticulocyte
B) Pronormoblast
C) Basophilic normoblast
D) Orthochromatic normoblast
✅ Correct Answer: B) Pronormoblast
Explanation: The pronormoblast is the first morphologically identifiable red cell precursor.
Reference: Henry’s Clinical Diagnosis.
7. The LAP (leukocyte alkaline phosphatase) score is typically elevated in:
A) Chronic myelogenous leukemia (CML)
B) Leukemoid reaction
C) Acute lymphoblastic leukemia (ALL)
D) Aplastic anemia
✅ Correct Answer: B) Leukemoid reaction
Explanation: LAP score is increased in leukemoid reactions but decreased in CML.
Reference: Rodak BF, et al.
8. A patient with chronic lymphocytic leukemia (CLL) would likely have which of the following findings?
A) Increased blasts
B) Hypersegmented neutrophils
C) Smudge cells
D) Döhle bodies
✅ Correct Answer: C) Smudge cells
Explanation: Fragile lymphocytes (smudge cells) are characteristic of CLL.
Reference: McKenzie SB.
9. The most common cause of hereditary spherocytosis is a defect in which protein?
A) Hemoglobin
B) Spectrin
C) Fibrinogen
D) Actin
✅ Correct Answer: B) Spectrin
Explanation: Spectrin deficiency leads to membrane instability and spherocyte formation.
Reference: Henry’s Clinical Diagnosis.
10. Which of the following is the most appropriate test to confirm a suspected diagnosis of PNH (Paroxysmal Nocturnal Hemoglobinuria)?
A) Coombs test
B) Flow cytometry for CD55/CD59
C) Osmotic fragility test
D) Hemoglobin electrophoresis
✅ Correct Answer: B) Flow cytometry for CD55/CD59
Explanation: CD55 and CD59 are GPI-anchored proteins absent in PNH cells.
Reference: Rodak BF.
11. Which of the following findings is most consistent with megaloblastic anemia?
A) Target cells
B) Microcytic hypochromic cells
C) Oval macrocytes and hypersegmented neutrophils
D) Spherocytes
✅ Correct Answer: C) Oval macrocytes and hypersegmented neutrophils
Explanation: These findings are hallmarks of B12/folate deficiency.
Reference: McKenzie SB.
12. In iron deficiency anemia, the TIBC is typically:
A) Decreased
B) Increased
C) Normal
D) Variable
✅ Correct Answer: B) Increased
Explanation: The body increases transferrin to compensate for low iron.
Reference: Henry’s Clinical Diagnosis.
13. Which of the following is a characteristic finding in chronic myelogenous leukemia (CML)?
A) Auer rods
B) Philadelphia chromosome
C) Increased LAP score
D) Smudge cells
✅ Correct Answer: B) Philadelphia chromosome
Explanation: The t(9;22) translocation (Philadelphia chromosome) is diagnostic of CML.
Reference: Rodak BF.
14. Which RBC abnormality is associated with G6PD deficiency following oxidative stress?
A) Target cells
B) Spherocytes
C) Bite cells
D) Elliptocytes
✅ Correct Answer: C) Bite cells
Explanation: Bite cells form when Heinz bodies are removed by the spleen.
Reference: McKenzie SB.
15. What is the key feature of polycythemia vera?
A) Decreased RBC mass
B) JAK2 mutation
C) Elevated erythropoietin
D) Bone marrow failure
✅ Correct Answer: B) JAK2 mutation
Explanation: The majority of PV patients have a JAK2 V617F mutation.
Reference: Henry’s Clinical Diagnosis.
16. The presence of Auer rods in blasts is indicative of:
A) ALL
B) AML
C) CLL
D) CML
✅ Correct Answer: B) AML
Explanation: Auer rods are needle-like inclusions specific to myeloid lineage in AML.
Reference: Rodak BF.
17. Which test is used to monitor heparin therapy?
A) PT
B) INR
C) aPTT
D) Bleeding time
✅ Correct Answer: C) aPTT
Explanation: Heparin prolongs aPTT by inhibiting factors in the intrinsic pathway.
Reference: McKenzie SB.
18. The Philadelphia chromosome results from a translocation between chromosomes:
A) 9 and 22
B) 8 and 14
C) 15 and 17
D) 11 and 22
✅ Correct Answer: A) 9 and 22
Explanation: This translocation forms the BCR-ABL fusion gene in CML.
Reference: Henry’s Clinical Diagnosis.
19. What is the expected bone marrow finding in aplastic anemia?
A) Hypercellularity
B) Increased megakaryocytes
C) Hypocellularity
D) Increased blasts
✅ Correct Answer: C) Hypocellularity
Explanation: Bone marrow is markedly hypocellular with fatty replacement.
Reference: Rodak BF.
20. Rouleaux formation is most commonly seen in:
A) Hereditary spherocytosis
B) Iron deficiency anemia
C) Multiple myeloma
D) Sickle cell disease
✅ Correct Answer: C) Multiple myeloma
Explanation: Increased plasma proteins in MM promote rouleaux.
Reference: McKenzie SB.
21. Which stain is used to differentiate myeloblasts from lymphoblasts?
A) PAS
B) Prussian blue
C) Myeloperoxidase (MPO)
D) Wright-Giemsa
✅ Correct Answer: C) Myeloperoxidase (MPO)
Explanation: MPO is positive in myeloblasts, helping distinguish from lymphoblasts.
Reference: Henry’s Clinical Diagnosis.
22. The M:E ratio in normal bone marrow is typically around:
A) 1:1
B) 2:1 to 4:1
C) 5:1
D) 10:1
✅ Correct Answer: B) 2:1 to 4:1
Explanation: Myeloid cells usually outnumber erythroid precursors.
Reference: Rodak BF.
23. In which of the following conditions would schistocytes most likely be found?
A) Iron deficiency anemia
B) Thalassemia
C) DIC
D) Aplastic anemia
✅ Correct Answer: C) DIC
Explanation: Schistocytes result from RBC fragmentation in microangiopathic hemolytic anemia like DIC.
Reference: McKenzie SB.
24. In hereditary elliptocytosis, the predominant RBC shape is:
A) Sickle-shaped
B) Round
C) Elliptical
D) Tear-drop
✅ Correct Answer: C) Elliptical
Explanation: Hereditary defects in spectrin or protein 4.1 lead to elliptical RBCs.
Reference: Henry’s Clinical Diagnosis.
25. The reticulocyte count is typically increased in which of the following?
A) Aplastic anemia
B) Hemolytic anemia
C) Iron deficiency anemia
D) Thalassemia trait
✅ Correct Answer: B) Hemolytic anemia
Explanation: In response to RBC destruction, the bone marrow increases reticulocyte production.
Reference: Rodak BF.
26. Which form of hemoglobin occurs naturally in circulation and contributes to normal oxygen delivery?
A. Methemoglobin
B. Deoxyhemoglobin ✅
C. Carboxyhemoglobin
D. Sulfhemoglobin
Explanation: Deoxyhemoglobin is the oxygen-depleted form that returns to the lungs for reoxygenation—physiologically normal.
27. What condition typically causes a right shift in the oxyhemoglobin dissociation curve, promoting oxygen release to tissues?
A. Alkalosis
B. Massive transfusion
C. Acidosis ✅
D. Presence of fetal hemoglobin
Explanation: Acidosis reduces oxygen affinity, increasing delivery to tissues. Other right-shift factors include 2,3-DPG and hyperthermia.
28. In a patient with aplastic anemia, which white cell type is most commonly seen on peripheral blood smear?
A. Lymphocytes ✅
B. Neutrophils
C. Monocytes
D. Eosinophils
Explanation: Aplastic anemia causes granulocytopenia; lymphocytes are relatively unaffected and become the predominant type.
29. What is the normal range for lymphocytes in an adult WBC differential?
A. 10–20%
B. 5–10%
C. 50–70%
D. 20–44% ✅
Explanation: In healthy adults, lymphocytes usually make up 20–44% of circulating WBCs.
30. A 4-year-old child presents with 60% lymphocytes on a CBC. What is the correct interpretation?
A. Leukemia
B. Normal finding for this age group ✅
C. Lymphopenia
D. Viral infection
Explanation: In toddlers (6 months to ~4 years), lymphocyte predominance is normal and part of physiological immune development.
31. Which automated differential result should prompt a manual smear review?
A. Monocytes = 15% ✅
B. Bands = 6%
C. Segmented neutrophils = 70%
D. Eosinophils = 2%
Explanation: Monocytes usually account for 1–8%. A value of 15% is elevated and warrants visual confirmation for abnormalities.
32. At which erythroid maturation stage does hemoglobin production cause cytoplasm to begin turning pink?
A. Reticulocyte
B. Pronormoblast
C. Polychromatic normoblast ✅
D. Basophilic normoblast
Explanation: Hemoglobin accumulation starts in the polychromatic normoblast, creating a gray-pink cytoplasm as RNA and Hb
33. Which condition does NOT cause a rightward shift in the hemoglobin oxygen dissociation curve?
A. Alkalosis ✅
B. Acidosis
C. Fever
D. Increased 2,3-DPG
Explanation: Alkalosis actually causes a leftward shift. Rightward shifts occur during acidosis, high 2,3-DPG, and hyperthermia.
34. What hemoglobin variant consists of four beta chains and is found in Hemoglobin H disease?
A. Hb H (β₄) ✅
B. Hb F (γ₄)
C. Hb A2 (α₂δ₂)
D. Hb A (α₂β₂)
Explanation: Hb H forms in alpha thalassemia when there are too few alpha chains, causing beta chains to form tetramers (β₄).
35. What lab abnormalities are caused by red cell autoagglutination at room temperature?
A. Increased hematocrit
B. Decreased MCV
C. Normal RBC count
D. Low RBC count with falsely high MCV ✅
Explanation: Agglutinated RBCs may be excluded from the count or appear oversized, falsely lowering RBC count and raising MCV.
36. What is the most typical blood cell pattern in hypersplenism?
A. Pancytosis
B. Cytopenias with splenomegaly ✅
C. Leukemoid reaction
D. Polycythemia
Explanation: An overactive spleen sequesters blood cells, leading to cytopenias despite normal marrow production
37. Which organ removes inclusions from red blood cells through a process called “pitting”?
A. Liver
B. Bone marrow
C. Spleen ✅
D. Kidneys
Explanation: The spleen can remove cell debris (e.g., Howell–Jolly bodies) while preserving the cell, known as pitting.
38. Which of the following is NOT characteristic of spherocytes?
A. Reduced surface area
B. Lack of central pallor
C. Poor osmotic tolerance
D. Increased deformability ✅
Explanation: Spherocytes are rigid due to membrane loss and are less deformable, making them prone to splenic destruction.
39. Which form of hemolysis is more typical in hereditary spherocytosis?
A. Intravascular
B. Complement-mediated
C. Extravascular ✅
D. Mechanical trauma-related
Explanation: In hereditary spherocytosis, hemolysis occurs in the spleen (extravascular) where rigid spherocytes are destroyed.
40. In which disorder is osmotic fragility increased?
A. Hereditary elliptocytosis
B. Hereditary spherocytosis ✅
C. Iron deficiency anemia
D. Thalassemia minor
Explanation: Spherocytes have less surface area and lyse more readily in hypotonic saline, raising osmotic fragility.
41. Sickle cell anemia is best categorized as what type of anemia based on red cell indices?
A. Normocytic, normochromic ✅
B. Microcytic, hypochromic
C. Normocytic, hypochromic
D. Macrocytic, normochromic
Explanation: In sickle cell disease, RBC size and hemoglobin content are generally normal; pathology arises from abnormal hemoglobin structure.
42. What is the major hemoglobin component in individuals with sickle cell trait?
A. Hemoglobin F
B. Hemoglobin C
C. Hemoglobin S
D. Hemoglobin A ✅
Explanation: People with sickle cell trait carry both Hb A and Hb S, but Hb A remains the majority component (50–70%).
43. What genetic mutation causes sickle cell disease?
A. Valine replaces glutamic acid at position 6 of the β-globin chain ✅
B. Lysine replaces glutamic acid in α-globin
C. Aspartate replaces lysine in β-globin
D. Valine replaces histidine in α-globin
Explanation: A single point mutation substitutes valine for glutamic acid in the β-chain, altering hemoglobin structure and function.
44. Hemoglobin C disease is characterized by all of the following EXCEPT:
A. Target cells
B. Hemoglobin C crystals
C. Lysine-for-glutamic acid substitution
D. Fast migration on alkaline electrophoresis ✅
Explanation: Hemoglobin C migrates slowly at alkaline pH due to its altered charge; it does not migrate fast.
45. Which hemoglobins migrate with Hb A2 on alkaline electrophoresis?
A. Hemoglobin S
B. Hemoglobin H
C. Hemoglobin F
D. Hemoglobin C ✅
Explanation: At pH 8.6, Hb C, E, and A2 migrate in the same region on electrophoresis.
46. Which of the following electrophoresis results is consistent with sickle cell trait?
A. Hb A = 40%, Hb S = 35%, Hb F = 5%
B. Hb A = 0%, Hb F = 95%, Hb A2 = 5%
C. Hb A = 60%, Hb S = 40%, Hb A2 = 2% ✅
D. Hb A = 80%, Hb S = 10%, Hb A2 = 10%
Explanation: Sickle trait shows both Hb A and Hb S, with Hb A being dominant and small amounts of A2 and F.
47. Which condition commonly leads to autosplenectomy due to repeated splenic infarction?
A. Sickle cell disease ✅
B. Thalassemia major
C. Hemoglobin C disease
D. Hereditary spherocytosis
Explanation: Repeated sickling in small vessels of the spleen leads to infarction and functional loss over time.
48. Paroxysmal nocturnal hemoglobinuria (PNH) is best described as:
A. A hereditary red cell enzyme defect
B. An acquired stem cell disorder with complement sensitivity ✅
C. An autosomal recessive trait
D. A congenital RBC membrane disorder
Explanation: PNH is an acquired clonal disorder affecting hematopoietic stem cells, making RBCs prone to complement-mediated lysis.
49. Which antibody is implicated in paroxysmal cold hemoglobinuria (PCH)?
A. Anti-i
B. Anti-P ✅
C. Anti-M
D. Anti-I
Explanation: Anti-P is a biphasic hemolysin that binds to RBCs in the cold and activates complement when rewarmed, causing hemolysis.
50. Which feature is NOT typical of intravascular hemolysis?
A. Hemoglobinemia
B. Hemoglobinuria
C. Methemoglobinemia ✅
D. Decreased haptoglobin
Explanation: Intravascular hemolysis results in free hemoglobin in blood and urine and low haptoglobin, but not methemoglobinemia.