Hematology MCQs with Answer and Explanations | Chapter 8

Answer: 6-8 micro metre

A typical human red blood cell has a diameter of approximately 6.2–8.2 µm [1, 2]. This size allows them to squeeze through tiny capillaries throughout the body.

The other options are incorrect:

• 10-15 micrometers: This option is incorrect as it exceeds the typical size range of a normal red blood cell.
• 15-20 micrometer: While some large red blood cells can be up to 20 micrometers, the standard size is smaller.
• None of these: There is a well-defined size range for healthy red blood cells.

Answer: 1/200

An RBC pipette is typically used in hemocytometry for counting red blood cells (RBCs) in a blood sample. The dilution factor determines the accuracy of the count. With an RBC pipette, a dilution of 1/200 means that one part of blood is diluted with 199 parts of a diluent solution. This dilution factor ensures that the RBC count falls within the optimal range for accurate counting.

The other options are incorrect:

• 1/10: This dilution factor is too low and would likely result in a concentration that is too high for accurate counting.
• 1/50: This dilution factor is also too low and would likely result in a concentration that is too high for accurate counting.
• 1/20: This dilution factor is too low and would likely result in a concentration that is too high for accurate counting.

Answer: Leukemia

Leukemia is a cancer of the blood and bone marrow that causes abnormal production of white blood cells. Leucocytosis, an elevated white blood cell count, is a common sign of leukemia as the body tries to fight the abnormal cell growth.

The other options are incorrect:

• Systemic lupus erythematosus (SLE): SLE can cause inflammation which may lead to a mild increase in white blood cells, but leucocytosis is not a typical feature.
• Rheumatoid arthritis: This is an autoimmune disease that primarily affects the joints. While some inflammatory markers might be elevated, leucocytosis is not a common finding.
• Aplastic anemia: This condition is characterized by a decrease in all blood cell lines, including white blood cells. Leucocytosis would be the opposite of what’s expected in aplastic anemia.

Answer: 3-4cm

An ideal blood smear length is typically between 3-4cm. This size allows for even distribution of blood cells across the slide and facilitates optimal visualization under a microscope. A smear within this range ensures there are enough cells for analysis while still being manageable to scan under the microscope lens.

The other options are incorrect:

• 1-2cm: Too short. A smear this small might not contain enough cells for accurate analysis. It may also be difficult to spread the blood evenly across such a short distance.
• 5-6cm: Too long. Excess smear length can make visualization under the microscope more difficult. A longer smear may also be more prone to tearing or damage during handling.
• 6-7cm: Excessively long. Similar to 5-6cm smears, this length can cause difficulties in viewing the entire smear under the microscope and increase the risk of damage.

Answer: 1.5-4.5 lakhs/mm? of blood

A normal platelet count in adults typically falls within the range of 1.5-4.5 lakhs/mm³ (150,000-450,000 platelets per microliter). Platelets are essential for blood clotting and wound healing.

The other options are incorrect:

• 50,000-1 lakhs/mm³ of blood: This range falls below the normal platelet count and might indicate thrombocytopenia, a condition of low platelet count which can lead to easy bruising or bleeding.
• 5000-11000 cells/mm³ of blood: This range is significantly lower than the normal platelet count and also uses an incorrect unit. Platelet count is typically measured in lakhs/mm³ (or microliters, µL), not just cells/mm³. This low value would be indicative of thrombocytopenia.
• 5-6 lakhs/mm³ of blood: This range exceeds the normal platelet count and might indicate thrombocytosis, a condition of high platelet count which can increase the risk of blood clots.

Answer: Neutrophils

Neutrophils, when stained with Leishman’s stain, exhibit fine violet-colored granules in their cytoplasm. This is due to the interplay of the acidic (eosin) and basic (methylene blue) components of the stain with the neutrophil’s specific granules.

The other options are incorrect:

• Eosinophils: These white blood cells have large, coarse orange-red colored granules after Leishman’s staining, easily distinguishable from the finer violet granules of neutrophils.
• Lymphocytes: Lymphocytes have very little cytoplasm and lack prominent granules. They appear with a pale blue cytoplasm and a darkly stained, typically round nucleus after Leishman’s stain.
• Monocytes: Monocytes have a pale grayish-blue cytoplasm with a characteristic horseshoe-shaped nucleus following Leishman’s stain. They may contain some fine azurophilic granules, but not the prominent violet granules seen in neutrophils.

Answer: 4mm?

The area of the central counting grid of an improved Neubauer chamber is typically 4 square millimeters.

The other options are incorrect:

• 3mm²: This is too small for the central counting area.
• 6mm²: This is too large for the central counting area.
• 9mm²: This is significantly larger than the central counting area.

Answer: Red blood cells

Erythropoiesis specifically refers to the process of producing red blood cells.

The other options are incorrect:

• Granulocytes: Granulocytes are a type of white blood cell, not red blood cells.
• Agranulocytes: Agranulocytes are another type of white blood cell, not red blood cells.
• Platelets: Platelets are involved in blood clotting and are not produced through erythropoiesis.

Answer: Electrophoresis

Electrophoresis is a common and reliable technique for separating and identifying different hemoglobin variants, aiding in the diagnosis of hemoglobinopathies.

The other options are incorrect:

• Sahli’s method: This method is used to estimate the hemoglobin concentration in blood, not to identify specific types of hemoglobin.
• Flame photometer: This instrument measures the concentration of elements like sodium and potassium, not the specific protein types like hemoglobin.
• Cyanmethemoglobin method: While this method can also estimate hemoglobin concentration, it doesn’t differentiate between different hemoglobin types.

Answer: N x 10000

The total erythrocyte count is calculated by multiplying the number of erythrocytes (red blood cells) per microliter of blood (N) by 10,000.

The other options are incorrect:

• N x 1000: This option is incorrect because it would result in an underestimate of the total erythrocyte count by a factor of 10.
• N x 50: This option is incorrect because it would result in an underestimate of the total erythrocyte count by a factor of 200.
• N x 2000: This option is incorrect because it would result in an overestimate of the total erythrocyte count by a factor of 5.

Answer: Hereditary spherocytosis

Hereditary spherocytosis causes red blood cells to be more spherical and fragile, making them more susceptible to rupturing in hypotonic solutions (increased osmotic fragility).

The other options are incorrect:

• Iron deficiency anemia: Red blood cells in iron deficiency anemia are typically microcytic (smaller) and have increased hemoglobin concentration, making them more resistant to rupturing.
• Sickle cell anemia: While sickle cells are abnormal, their fragility can vary depending on the specific mutation. They might not show a clear increase in osmotic fragility.
• Thalassemia: Thalassemia can lead to smaller red blood cells (microcytosis) with a slightly higher surface area to volume ratio. This can sometimes lead to increased osmotic fragility, but it’s not as pronounced as in hereditary spherocytosis.

Answer: 4.5 to 6.5 millions/”mm3″

This range is expressed in millions of cells per cubic millimeter (mm³), which is the standard unit for measuring RBC count.

The other options are incorrect:

• 80 – 160 millions/ml: This range is in millions of cells per milliliter (ml). While the total number of red blood cells might be similar, ml is a larger volume unit than mm³, so the concentration (count per unit volume) would be different.
• 4.5 to 6.5 lakhs /mm³: Lakhs is a term for hundreds of thousands, and this range is significantly lower than the normal RBC count in millions.
• None of the above: At least one of the provided options is within the normal range for RBC count.

Answer: Citrate

Sodium citrate is the most commonly used anticoagulant for coagulation studies. It works by chelating calcium ions, which are essential for the clotting cascade.

The other options are incorrect:

• Oxalate: While some specific coagulation tests might use oxalate, it’s not as widely used as citrate due to potential effects on certain clotting factors.
• EDTA: EDTA chelates metal ions like calcium and magnesium, which are necessary for many cellular functions, making it unsuitable for studying coagulation, which relies on these ions.
• Heparin: Heparin directly inhibits thrombin and other clotting factors, making it unsuitable for measuring clotting time accurately. It can be used for blood collection for other tests where clotting needs to be prevented.

Answer: All the above

Erythrocyte sedimentation rate (ESR) can be measured using various methods, including Westergren’s tube, Wintrobe’s tube, and Esrite tube.

• Westergren’s tube: Westergren’s tube is indeed used for measuring ESR, so it should be included among the correct options.
• Wintrobes tube: due to a spelling error. The correct term is “Wintrobe’s tube,” and it is also used for measuring ESR, so it should be included among the correct options.
• Esrite tube: There is no commonly known tube called the “Esrite tube” used for measuring ESR. It seems to be a fabrication or a misspelling of another method.

Answer: All the above

Bleeding time is a test that measures how long it takes for a small cut to stop bleeding. Various factors can influence this:

• Platelet dysfunction: Platelets are essential for forming blood clots. If they are dysfunctional or in low numbers (thrombocytopenia), they can’t adequately plug the wound, leading to prolonged bleeding time.
• Vitamin K deficiency: Vitamin K is necessary for the production of several clotting factors in the blood cascade. A deficiency can impair clot formation and increase bleeding time.
• Severe clotting factor deficiency: Blood clotting factors work together in a cascade. If one or more factors are severely deficient, the entire clotting process can be disrupted, leading to prolonged bleeding time.

Answer: unstained unfixed smear

Supravital staining involves staining living cells without fixation. Therefore, the smear used for supravital staining should be unstained and unfixed to preserve the cellular integrity and allow for the visualization of cellular processes.

The other options are incorrect:

• Fixed and stained smear: Fixation preserves the cells but kills them, making them unsuitable for supravital staining.
• Fixed smear: Similar to above, fixation renders the cells unusable for supravital staining.
• All of the above: Only unstained and unfixed smears are appropriate for supravital staining.

Answer: (1) and (2)

An RBC pipette is a specialized tool designed to deliver a precise volume of blood diluted for counting both red blood cells (RBCs) and platelets.

Answer: Metal poisoning

Basophilic stippling refers to the presence of abnormally coarse blue granules within red blood cells seen on a blood smear. While several conditions can be associated with it, metal poisoning, particularly lead poisoning, is a well-known cause.

The other options are incorrect:

• G6PD deficiency: This condition can cause hemolytic anemia, but it doesn’t typically cause basophilic stippling.
• Splenectomy: The spleen removes damaged red blood cells, and its absence might affect red blood cell morphology, but it’s not a direct cause of basophilic stippling.
• Erythroblastosis fetalis: This is a condition involving Rh incompatibility between mother and baby. While abnormal red blood cell development can occur, basophilic stippling is not a common finding.

Answer: Haemoglobin

Haemoglobin is a protein within red blood cells that contains iron. This iron binds to oxygen molecules, allowing red blood cells to transport oxygen throughout the body. Haemoglobin is the primary reason blood appears red, as it reflects red and yellow light wavelengths while absorbing most others.

The other options are incorrect:

• Myoglobin: Another protein that binds oxygen, but it’s found primarily in muscle tissue, not red blood cells.
• Globulin: A type of protein found in blood plasma with various functions, but it doesn’t contribute to blood color.
• Albumin: The most abundant protein in blood plasma, but it’s also colorless and doesn’t affect blood color.

Answer: Methanol

Methanol is the most common fixative used for routine blood smears before Giemsa staining. It quickly fixes and preserves the cell morphology while allowing good staining characteristics.

The other options are incorrect:

• Acetone: While acetone can be used as a fixative, it’s not the preferred choice for blood smears due to potentially harsher effects on cell morphology compared to methanol.
• Acetic acid: This is a weak acid and not typically used as a fixative for blood smears. It might cause excessive cell lysis.
• Chloroform: Chloroform is a solvent with some fixative properties, but it’s not a common choice for blood smears due to safety concerns and potential for damaging cellular components.

Answer: Millimetre/hour

The Erythrocyte Sedimentation Rate (ESR) test measures the rate at which red blood cells settle in a standardized tube over a period of one hour. The distance settled is measured in millimeters (mm), and the result is reported as the distance settled per hour (mm/hr).

The other options are incorrect:

• Centimetre/minute: This unit is incorrect for both time (minutes) and distance (centimetres). ESR is measured in mm/hr.
• Millimetre/minute: This unit is incorrect for the time measurement. ESR is measured over one hour.
• Centimetre/hour: This unit is incorrect for the distance measurement. ESR is measured in millimetres settled per hour.

Answer: Sickle celi anaemia

Drepanocytes, also known as sickle cells, are seen in sickle cell anaemia, a genetic disorder characterized by abnormal, crescent-shaped red blood cells.

The other options are incorrect:

• Alcoholism: Alcoholism does not typically cause the formation of drepanocytes or sickle cells.
• Thalassaemia: Thalassaemia is a genetic disorder affecting the production of hemoglobin, but it does not typically result in the formation of sickle cells.
• Uremia: Uremia, a condition associated with kidney dysfunction, does not typically result in the formation of sickle cells.

Answer: Acute promyelocytic leukaemia

DIC (Disseminated Intravascular Coagulation) is a complication that can occur in various conditions, including APL. APL is a specific type of acute leukemia where abnormal white blood cells can trigger widespread activation of clotting throughout the body, leading to DIC.

Incorrect Options:

• Chronic myeloid leukaemia: While chronic myeloid leukaemia (CML) is a type of leukemia, DIC is not typically a complication associated with it.
• Hairy cell leukaemia: Hairy cell leukaemia is a rare type of chronic lymphocytic leukaemia (CLL). DIC is not typically associated with hairy cell leukaemia.
• Chronic lymphocytic leukaemia: Chronic lymphocytic leukaemia (CLL) is characterized by the accumulation of abnormal B lymphocytes. DIC is not typically associated with CLL.

Answer: Defective platelet aggregation

Glanzmann’s thrombasthenia is a rare inherited bleeding disorder characterized by a deficiency in a specific protein needed for platelets to clump together (aggregate) during clot formation. This defective aggregation is the hallmark feature of the disease, leading to abnormal bleeding.

The other options are incorrect:

• Defective platelet adhesion: Glanzmann’s disease primarily involves defective platelet aggregation, not platelet adhesion.
• Normal clot retraction: Glanzmann’s disease affects platelet function and aggregation, but it does not typically involve clot retraction.
• None of these: Glanzmann’s disease is specifically associated with defective platelet aggregation.

Answer: 11 cm

The standard length of a Wintrobe’s hematocrit tube is approximately 11 centimeters.

Incorrect Options:

• 9 cm: It presents a shorter length than the typical Wintrobe’s hematocrit tube.
• 19 cm: It presents a longer length than the typical Wintrobe’s hematocrit tube.
• 12 cm: It presents a slightly longer length than the typical Wintrobe’s hematocrit tube.

Answer: HbF

The Betke-Kleihauer method is used to detect fetal hemoglobin (HbF) in maternal blood. It is commonly used in cases of maternal-fetal hemorrhage to determine the extent of fetal blood loss into the maternal circulation.

The other options are incorrect:

• HbA: The Betke-Kleihauer method is not used to detect adult hemoglobin (HbA).
• HbC: This method is not used to detect hemoglobin C (HbC).
• None of these: The Betke-Kleihauer method is specifically used to detect fetal hemoglobin (HbF).

Answer: Impedence method

The Coulter counter is based on the impedance method, which measures changes in electrical resistance as cells pass through a small aperture. This method allows for accurate counting and sizing of cells in a blood sample.

The other options are incorrect:

• Light reflection: The Coulter counter does not rely on light reflection for cell counting; it is based on impedance measurement.
• Light refraction: Similar to light reflection, the Coulter counter does not utilize light refraction for cell counting.
• All the above: While the Coulter counter counts cells, it specifically does so using the impedance method, not light reflection or refraction.

Answer: Multiple myeloma

Bence Jones protein is a type of abnormal protein (immunoglobulin light chain) that is frequently found in the urine of individuals with multiple myeloma, a type of cancer that affects plasma cells in the bone marrow.

The other options are incorrect:

• Nephrotic syndrome: Bence Jones protein is not typically associated with nephrotic syndrome, which is characterized by proteinuria due to kidney damage.
• Cirrhosis of liver: Bence Jones protein is not typically associated with cirrhosis of the liver, which is characterized by scarring of the liver tissue.
• Hepatitis: Bence Jones protein is not typically associated with hepatitis, which is inflammation of the liver usually caused by viral infection.

Answer: A heavy buffy coat

A heavy buffy coat, which is an increased presence of white blood cells in the layer between the packed red blood cells and the plasma, may suggest the presence of leukemia, as it indicates an elevated white blood cell count.

The other options are incorrect:

• A high hematocrit: A high hematocrit, or an elevated percentage of red blood cells in the blood, is not typically indicative of leukemia. Leukemia is a cancer of the white blood cells, not the red blood cells.
• Hemolysis: Hemolysis, the rupture of red blood cells and release of hemoglobin into the plasma, is not typically indicative of leukemia. It is more often associated with other conditions such as transfusion reactions or certain diseases affecting red blood cells.
• Icteric plasma: Icteric plasma, which appears yellow due to elevated bilirubin levels, is not typically indicative of leukemia. It may suggest liver dysfunction or other conditions affecting bilirubin metabolism.

Answer: Size of the particle being counted

Some automated blood cell counters operate based on the principle of detecting and counting cells based on their size. By passing cells through a narrow aperture, the counter can measure the size of each cell as it passes, allowing for the determination of various blood parameters.

The other options are incorrect:

• Weight of the hemoglobin in the red cell: While hemoglobin content is essential for determining parameters like mean corpuscular hemoglobin concentration (MCHC), automated counters typically do not measure hemoglobin weight directly for cell counting.
• Value of the cell indices: Cell indices such as mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) are calculated based on cell measurements but are not the principles by which automated counters count cells.
• Amount of hemoglobin in the red cell: While hemoglobin content is crucial for assessing red blood cell function and parameters, it is not typically used as the primary principle for cell counting in automated counters.

Answer: Hemolytic

Severe burns can lead to hemolytic anemia due to the destruction of red blood cells (hemolysis) caused by factors such as tissue damage, inflammation, and oxidative stress associated with the burn injury.

The other options are incorrect:

• Microcytic: Microcytic anemia is characterized by small red blood cells and is typically associated with conditions such as iron deficiency anemia or thalassemia, not severe burns.
• Macrocytic: Macrocytic anemia is characterized by large red blood cells and is typically associated with conditions such as vitamin B12 deficiency or folate deficiency, not severe burns.
• Aplastic: Aplastic anemia is characterized by a deficiency of all types of blood cells (red blood cells, white blood cells, and platelets) due to bone marrow suppression or failure, which is not typically associated with severe burns.

Answer: Nasal secrection for eosinophiles

Hansel’s stain is a diagnostic tool used in laboratories to specifically identify eosinophils, a type of white blood cell. It’s particularly effective in detecting eosinophils in fluids like nasal secretions, which can be helpful in diagnosing allergies.

The other options are incorrect:

• Phagocytic neutrophils: Hansel’s stain is not optimized for identifying neutrophils, another type of white blood cell.
• Circulating eosinophils: While eosinophils can be present in blood, Hansel’s stain is not typically used for blood analysis. Complete blood count (CBC) is a more common test for this purpose.
• Leukocytes in spinal fluid: Hansel’s stain is not the preferred method for analyzing cells in cerebrospinal fluid (CSF). Other stains like Gram stain or cytology are used for CSF analysis.

Answer: Plasma only

Fibrinogen is a clotting factor present in blood plasma. During blood clotting, fibrinogen is converted into fibrin, which forms the mesh of a blood clot. Since serum is blood plasma that has undergone clotting and removed the clotting factors, it wouldn’t contain fibrinogen for measurement.

The other options are incorrect:

• Serum only: As mentioned above, serum lacks fibrinogen due to clotting.
• Any body fluid: Fibrinogen is a specific protein found in blood plasma, not generally present in other bodily fluids.
• Either serum or plasma: Fibrinogen is not present in significant amounts in serum due to clotting.

Answer: Reticulocytes

Brilliant cresyl blue and new methylene blue stains are selectively taken up by ribosomal RNA, which is abundant in immature red blood cells called reticulocytes. This allows for easy identification and counting of reticulocytes in a blood smear.

The other options are incorrect:

• Howell-Jolly bodies: These are residual cellular material in some red blood cells, not reticulocytes. Wright-Giemsa stain is typically used to visualize Howell-Jolly bodies.
• Malaria: Malaria parasites are identified within red blood cells using Giemsa stain, not brilliant cresyl blue or new methylene blue.
• Platelets: Platelets are much smaller than red blood cells and require different stains, like Wright-Giemsa, for visualization due to their lack of internal structures.

Answer: Platelet function

Clot retraction, the process by which a blood clot contracts and becomes denser, is primarily a function of platelets. Therefore, it can be employed as an indicator of platelet function, reflecting the ability of platelets to aggregate and stabilize a clot.

The other options are incorrect:

• Factor VII deficiency: Factor VII is involved in the initiation of the coagulation cascade by activating factors IX and X. Clot retraction is not typically used as an indicator of Factor VII deficiency.
• Factor X deficiency: Factor X is a key component of the coagulation cascade, serving as the link between the intrinsic and extrinsic pathways. Clot retraction is not typically used as an indicator of Factor X deficiency.
• Hemophilia: Hemophilia is a bleeding disorder caused by deficiency or dysfunction of clotting factors VIII (hemophilia A) or IX (hemophilia B). Clot retraction is not typically used as an indicator of hemophilia.

Answer: 0.50% NaCl

Hemolysis begins in 0.50% NaCl in the screening or presumptive test for the osmotic fragility of red cells.

The other options are incorrect:

• 0.90% NaCl: Hemolysis begins before 0.90% NaCl in the screening test.
• 1.34% NaCl: Hemolysis begins after 1.34% NaCl in the screening test.
• 0.85% NaCl: Hemolysis begins before 0.85% NaCl in the screening test.

Answer: Hemolytic

Severe burns are typically associated with hemolytic anemia due to the destruction of red blood cells.

The other options are incorrect:

• Macrocytic: Macrocytic anemia is not typically associated with severe burns.
• Microcytic: Microcytic anemia is not typically associated with severe burns.
• Aplastic: Aplastic anemia is not typically associated with severe burns.

Answer: 6-8 micro metre

A normal red blood cell typically has a size ranging from 6 to 8 micrometers.

The other options are incorrect:

• 10-15 micrometers: This range is larger than the typical size of a normal red blood cell.
• 15-20 micrometers: This range is larger than the typical size of a normal red blood cell.
• None of these: The size of a normal red blood cell typically falls within the range of 6 to 8 micrometers.

Answer: RBC and WBC

A high background count on an automated blood cell counter can affect the accurate counting of both red blood cells (RBC) and white blood cells (WBC), as the background noise can interfere with the detection of individual cells.

The other options are incorrect:

• WBC and Hgb: A high background count typically does not affect hemoglobin (Hgb) measurements on an automated blood cell counter.
• Hct and WBC: Hematocrit (Hct) measurements are less likely to be affected by a high background count on an automated blood cell counter compared to RBC and WBC counts.
• RBC and Hgb: While a high background count can affect RBC counts, it typically does not have a significant impact on hemoglobin (Hgb) measurements on an automated blood cell counter.

Answer: Diluting fluid

On most automated cell counters, background counts are made using diluting fluid, which is a solution specifically designed to dilute the blood sample and minimize background noise, allowing for accurate cell counting.

The other options are incorrect:

• Lysing reagent only: Lysing reagents are typically used to lyse red blood cells in whole blood samples for specific assays but are not typically used for background counts on automated cell counters.
• Highly-diluted blood: While dilution is involved in the counting process, highly-diluted blood alone is not typically used for background counts on automated cell counters.
• Distilled water: Distilled water is not typically used for background counts on automated cell counters, as it does not provide the necessary dilution and buffer properties required for accurate counting.

Answer: RNA remnants

Reticulocytes, which are immature red blood cells, contain RNA remnants from their precursor cells, reflecting their ongoing synthesis of hemoglobin.

The other options are incorrect:

• Howell-Jolly bodies: Howell-Jolly bodies are small, round inclusions found in red blood cells, typically associated with certain conditions such as splenectomy or megaloblastic anemia. They are not present in reticulocytes.
• DNA remnants: Reticulocytes contain RNA remnants, but they do not contain DNA remnants.
• Basophilic granules: Basophilic granules are not typically found in reticulocytes; they are more commonly associated with basophils or certain other cell types.

Answer: 0.1 mm

The distance between the ruled surface and the cover slip of the hemacytometer is typically 0.1 millimeters (mm), which is essential for accurate cell counting under a microscope.

The other options are incorrect:

• 1.0 mm: This distance is too large for the correct use of a hemacytometer; it would likely result in inaccurate cell counting.
• 0.1 cm: While 0.1 centimeters (cm) is equivalent to 1.0 mm, it is not the standard unit used for the distance between the ruled surface and the cover slip of a hemacytometer.
• 1.0 cm: This distance is too large for the correct use of a hemacytometer; it would likely result in inaccurate cell counting.

Answer: More dense

During the maturation of a blood cell, the nuclear chromatin pattern becomes more dense as the cell undergoes differentiation and specialization.

The other options are incorrect:

• Less dense: The nuclear chromatin pattern typically becomes more dense as the cell matures, not less dense.
• Finer: While the chromatin pattern may become more organized, it typically becomes denser rather than finer.
• More acidic: The change in chromatin density during maturation is not related to acidity; rather, it reflects changes in the organization and compaction of chromatin.

Answer: Bacterial infection

An elevated leukocyte count with increased numbers of neutrophilic granulocytes usually indicates a bacterial infection, as neutrophils are the first responders to bacterial pathogens.

The other options are incorrect:

• Infectious mononucleosis: Infectious mononucleosis typically presents with an elevated leukocyte count but with increased numbers of atypical lymphocytes, not neutrophils.
• Allergic reaction: Allergic reactions may result in an elevated leukocyte count, but the predominant cell type involved is often eosinophils, not neutrophils.
• Viral infection: While viral infections can lead to leukocytosis, the increase in neutrophils is typically less prominent compared to bacterial infections. Viral infections may involve lymphocytes more prominently than neutrophils.

Answer: Reticulocytes

Reticulocytes are immature red blood cells, and stains like Brilliant cresyl blue or new methylene blue are commonly used in laboratory settings to facilitate their counting.

The other options are incorrect:

• Malaria: Stains like Giemsa are typically used for diagnosing malaria by highlighting the parasites within red blood cells.
• Platelets: Stains such as Wright-Giemsa are utilized for platelet counting and examination, but not Brilliant cresyl blue or new methylene blue.
• Howell-Jolly bodies: These are nuclear remnants found in erythrocytes, and staining methods such as Wright stain or Romanowsky stains are more appropriate for their visualization.

Answer: Heniz bodies

Supravital staining of red cells with a deficiency of G-6-PD (glucose-6-phosphate dehydrogenase) will reveal the presence of Heinz bodies, which are denatured hemoglobin precipitates, indicative of oxidative damage in erythrocytes.

The other options are incorrect:

• Howell-Jolly bodies: These are nuclear remnants found in red blood cells, typically seen in conditions like asplenia or after splenectomy, and are not related to G-6-PD deficiency.
• Plasmodium species: Staining methods such as Giemsa are used to detect malaria parasites (Plasmodium species) within red blood cells, but they are not related to G-6-PD deficiency.
• Rubriblasts: These are immature red blood cells, specifically the earliest recognizable stage of erythropoiesis, and are not associated with G-6-PD deficiency.

Answer: Hemoglobin

The majority of iron in an adult is found as a constituent of hemoglobin, the protein in red blood cells responsible for transporting oxygen.

The other options are incorrect:

• Hemosiderin: This is an iron storage complex formed by the breakdown of ferritin and is found in tissues as a result of excess iron storage, not as the primary form of iron in the body.
• Myoglobin: Myoglobin is a protein found in muscle cells that stores oxygen for use during muscle contraction. While it contains iron, it is not the primary form of iron in the body.
• Transferrin: Transferrin is a blood plasma glycoprotein that binds and transports iron throughout the body, but it does not contain the majority of iron in the adult body.

Answer: Provide reduced glutathione to prevent oxidation of hemoglobin

The main function of the hexose monophosphate shunt in the erythrocyte is to provide reduced glutathione, which acts as an antioxidant, protecting hemoglobin from oxidative damage.

The other options are incorrect:

• Regulate the level of 2,3 DPG: While the hexose monophosphate shunt indirectly influences the levels of 2,3-diphosphoglycerate (2,3 DPG), its primary function is not direct regulation of this molecule.
• Prevent the reduction of heme iron: This function is not associated with the hexose monophosphate shunt. The reduction of heme iron is typically regulated by other enzymatic processes.
• Provide energy for membrane maintenance: Although the hexose monophosphate shunt does produce NADPH, which can be used for various cellular processes including membrane maintenance, its primary role in erythrocytes is to provide reduced glutathione for antioxidant defense.

Answer: In the ferrous state

For hemoglobin to combine reversibly with oxygen, the iron must be in the ferrous state (Fe2+), allowing it to bind oxygen molecules.

The other options are incorrect:

• Complexed with haptoglobin: Haptoglobin is a protein in the blood that binds free hemoglobin to prevent its toxicity, but it is not involved in the reversible binding of oxygen to hemoglobin.
• Freely circulating in the cytoplasm: Hemoglobin is found within red blood cells, not freely circulating in the cytoplasm.
• Attached to transferrin: Transferrin is a blood plasma glycoprotein that binds and transports iron throughout the body, but it is not directly involved in the reversible binding of oxygen to hemoglobin.

Answer: Myeloid metaplasia

Myeloid metaplasia, also known as myelofibrosis, is a bone marrow disorder characterized by the proliferation of abnormal bone marrow cells. Teardrop cells and abnormal platelets are most characteristically seen in this disease state.

The other options are incorrect:

• Hemolytic anemia: Hemolytic anemia is characterized by the premature destruction of red blood cells, but teardrop cells and abnormal platelets are not typically associated with this condition.
• Multiple myeloma: Multiple myeloma is a cancer of plasma cells, and while it can lead to various hematological abnormalities, teardrop cells and abnormal platelets are not specifically characteristic of this disease.
• G-6PD deficiency: G-6PD deficiency is a genetic disorder affecting red blood cells, leading to their increased vulnerability to oxidative stress, but it is not typically associated with teardrop cells and abnormal platelets.