Question 1

Which metallic element is present in haemoglobin?

Accepted Answer

Answer reason: Hemoglobin contains heme groups with a central ferrous iron (Fe2+) atom that binds oxygen reversibly. This iron is essential for oxygen transport from the lungs to tissues. Deficiency or impaired iron incorporation leads to microcytic, hypochromic anemia. Aluminum, lead, and copper are not structural constituents of hemoglobin.

Question 2

Thalassemia is a hereditary disease that affects...?

Accepted Answer

Answer reason: Thalassemia is an inherited hemoglobinopathy characterized by decreased or absent synthesis of globin chains, leading to microcytic, hypochromic anemia. The primary pathology involves red blood cells and hemoglobin within the blood. While severe anemia can cause secondary effects on the heart or lungs, the disease directly affects the blood.

Question 3

Deficiency of red blood cell in the human body is called....?

Accepted Answer

Answer reason: A deficiency in red blood cells or hemoglobin is termed anemia, leading to reduced oxygen-carrying capacity and symptoms like fatigue and pallor. Malaria and pneumonia are infectious diseases, not RBC deficiencies. Fever is a nonspecific symptom rather than a hematologic condition. Therefore, the correct term is anemia.

Question 4

Platelets are also called...?

Accepted Answer

Answer reason: Platelets are anucleate cell fragments involved in hemostasis and are also called thrombocytes. They are derived from megakaryocytes in the bone marrow. Leukocytes are white blood cells and erythrocytes are red blood cells, which are different cell lines. Megakaryocytes are the precursor cells that shed platelets, not another name for them.

Question 5

Which vitamin is essential for blood clotting?

Accepted Answer

Answer reason: Vitamin K is required in the liver for gamma-carboxylation of clotting factors II, VII, IX, and X, as well as proteins C and S, enabling them to bind calcium and function in coagulation. Deficiency leads to impaired clotting and bleeding. Vitamins A, C, and D do not have a primary role in activating coagulation factors.

Question 6

Which vitamin helps in blood clotting?

Accepted Answer

Answer reason: Vitamin K is a critical cofactor for hepatic gamma-carboxylation of glutamate residues on clotting factors II, VII, IX, and X, as well as proteins C and S. This modification enables calcium binding and activation of the coagulation cascade, promoting normal hemostasis. Deficiency leads to bleeding tendency and elevated PT/INR, which is why newborns receive prophylactic vitamin K.

Question 7

Which cells in the blood do not have a nucleus?

Accepted Answer

Answer reason: Mature erythrocytes (red blood cells) in peripheral blood are anucleate, having expelled their nuclei during erythropoiesis to maximize hemoglobin content and flexibility. All listed leukocytes—lymphocytes, monocytes, basophils, and neutrophils—retain nuclei. Therefore, the only correct choice is erythrocyte.

Question 8

The liquid part of blood is called ____?

Accepted Answer

Answer reason: Plasma is the liquid extracellular matrix of blood that carries cells and dissolved substances such as proteins, electrolytes, nutrients, and hormones. Serum is plasma after clotting and lacks fibrinogen and clotting factors. Lymph is a separate interstitial fluid within the lymphatic system. Platelets are cellular fragments involved in clotting, not a liquid component.

Question 9

Erythrocyte mature in which site of the body?

Accepted Answer

Answer reason: Erythrocytes develop from erythroid progenitors and mature in the red bone marrow under the influence of erythropoietin. Reticulocytes are then released into the bloodstream, where they complete final maturation. The spleen and liver can serve as sites of extramedullary hematopoiesis mainly in fetal life or certain pathologic states. “Lymphocyte” is a cell type, not an anatomical site.

Question 10

Most commonly used Blood bag anticoagulant is....?

Accepted Answer

Answer reason: CPDA-1 (citrate–phosphate–dextrose–adenine) is the standard anticoagulant-preservative used for whole blood collection. Citrate chelates calcium to prevent clotting, while dextrose, phosphate, and adenine support ATP and 2,3-DPG, allowing storage up to about 35 days. ACD is older with shorter storage, and CPD lacks adenine so supports a shorter shelf life. SAGM is an additive solution for packed RBCs, not the primary anticoagulant in the collection bag.

Question 11

Picogram is the measurement unit of?

Accepted Answer

Answer reason: MCH (mean corpuscular hemoglobin) represents the average mass of hemoglobin per red blood cell and is expressed in picograms (pg), typically about 27–33 pg. MCV is a measure of cell volume and is reported in femtoliters (fL). MCHC reflects hemoglobin concentration within RBCs and is expressed in g/dL or g/L. Therefore, the correct unit association for picogram is MCH.

Question 12

In whole blood, the buffycoat portion is constituent about...?

Accepted Answer

Answer reason: The buffy coat is the thin layer between plasma and packed red cells after centrifugation and consists primarily of leukocytes and platelets. In normal whole blood, this layer accounts for about 1% of volume. By contrast, erythrocytes (hematocrit) are ~45% and plasma is ~55%. Therefore, 1% is the best estimate for buffy coat composition.

Question 13

Fluid part of blood is known as...?

Accepted Answer

Answer reason: Plasma is the straw-colored liquid component of blood that makes up about 55% of its volume and serves as the medium for transporting cells and solutes. It consists mainly of water with dissolved proteins, electrolytes, nutrients, and waste products. Platelets and blood cells are the formed elements suspended within the plasma, not the fluid itself.

Question 14

Which Vitamin activates the proteins and calcium required for blood clotting?

Accepted Answer

Answer reason: Vitamin K is a cofactor for gamma-carboxylation of glutamate residues on clotting factors II, VII, IX, and X and proteins C and S. This modification enables these proteins to bind calcium and interact with phospholipid surfaces, activating the coagulation cascade. Deficiency impairs clot formation and leads to bleeding tendencies.

Question 15

Normal platelet count in human being is-?

Accepted Answer

Answer reason: Normal adult platelet count is approximately 150,000–400,000/µL (some references extend to 450,000). Among the choices, 100,000–400,000 is the only range that includes the standard normal span. The lower ranges (25,000–50,000 and 50,000–100,000) indicate thrombocytopenia, while 400,000–600,000 suggests thrombocytosis. Therefore, option C is the best answer.

Question 16

Blood groups were first discovered by-?

Accepted Answer

Answer reason: Karl Landsteiner identified the ABO blood group system in 1901 by demonstrating agglutination reactions between different human sera and red cells. This discovery explained transfusion incompatibility and laid the foundation for safe blood transfusion. Robert Koch is known for germ theory and bacterial pathogens, Paul Ehrlich for immunology and chemotherapy, and Antonie van Leeuwenhoek for microscopy.

Question 17

Which one of the following ions helps in blood clotting-?

Accepted Answer

Answer reason: Calcium ions (factor IV) are essential cofactors in multiple steps of the coagulation cascade, facilitating activation of clotting factors and the conversion of prothrombin to thrombin. Removing or chelating calcium (e.g., with citrate) prevents blood from clotting, demonstrating its necessity. Potassium, manganese, and phosphate do not serve as key cofactors in physiologic coagulation.

Question 18

Place where RBC s are produced is?

Accepted Answer

Answer reason: In adults, erythropoiesis occurs in the red bone marrow of axial and proximal long bones under the stimulation of erythropoietin from the kidneys. The liver is a major hematopoietic site only in the fetus. Blood is the transport medium, not the site of production, and testes are unrelated to hematopoiesis.

Question 19

Blood is ...?

Accepted Answer

Answer reason: Blood is a specialized connective tissue composed of formed elements (erythrocytes, leukocytes, platelets) suspended in an extracellular matrix (plasma). By histologic definition, a tissue is a group of cells plus matrix performing a common function, which blood fulfills. It is not an organ or a whole system, but a tissue that contributes to the circulatory system.

Question 20

Percentage of plasma in blood is?

Accepted Answer

Answer reason: Whole blood is composed of approximately 55% plasma and 45% formed elements (hematocrit) in adults. Plasma is the liquid component containing water, electrolytes, proteins, and other solutes. Therefore, the percentage of plasma in blood is about 55%.

Question 21

The commenest Anaemia in Nepal...?

Accepted Answer

Answer reason: Iron deficiency anemia is the most prevalent anemia worldwide and in South Asia, including Nepal. It commonly results from inadequate dietary iron intake, chronic blood loss (e.g., hookworm infection, menstruation), and increased requirements in pregnancy. Other listed causes—pernicious anemia, hemolytic anemia, and thalassemia—are far less common in the general population.

Question 22

Blood is?

Accepted Answer

Answer reason: Blood is a specialized connective tissue composed of formed elements (erythrocytes, leukocytes, platelets) suspended in plasma. It functions in transport, defense, and homeostasis. It is not a single cell, an individual organ, or an entire organ system.

Question 23

Leukemia is a cancer of ?

Accepted Answer

Answer reason: Leukemia is a group of hematologic malignancies characterized by malignant proliferation of leukocyte precursors in the bone marrow with spillover into the peripheral blood. It primarily affects the blood and blood-forming tissues, leading to abnormal numbers and function of white blood cells. Thus, it is classified as a cancer of the blood.

Question 24

Which blood group has no antigen?

Accepted Answer

Answer reason: In the ABO blood group system, type O red blood cells lack both A and B antigens on their surface. As a result, individuals with type O have neither A nor B antigens but typically possess anti-A and anti-B antibodies in plasma. This absence of A/B antigens underlies why type O blood is compatible as a universal donor for RBCs.

Question 25

Study of blood is called…?

Accepted Answer

Answer reason: Hematology is the branch of science that studies blood, its components, formation, and disorders. Oncology focuses on cancers and tumors, embryology studies prenatal development, and cytology examines cells broadly rather than blood specifically. Therefore, the correct term for the study of blood is hematology.

Question 26

How many blood groups are found in human body?

Accepted Answer

Answer reason: In the ABO blood group system, humans have four major blood groups: A, B, AB, and O, determined by the presence or absence of A and B antigens on red blood cells. These groups are the fundamental classification used for transfusion compatibility. While each group can be Rh positive or negative (yielding eight types), the number of ABO groups remains four.

Question 27

Which blood group is universal Acceptor?

Accepted Answer

Answer reason: AB positive individuals express A, B, and Rh(D) antigens on their red cells and therefore lack anti-A, anti-B, and anti-D antibodies in their plasma. As a result, they can receive red blood cells from any ABO and Rh type without hemolytic reactions. Thus, AB+ is considered the universal recipient for RBC transfusions.

Question 28

What is the amount of blood in normal human body?

Accepted Answer

Answer reason: Average adult blood volume is about 70 mL/kg, which is roughly 5 liters in a 70‑kg person. Normal range is approximately 4.5–5.5 liters and varies with body size and sex. Therefore, 5 litre is the best single answer.

Question 29

What blood type is considered the universal donor?

Accepted Answer

Answer reason: Type O negative red blood cells lack A, B, and Rh(D) antigens, so they are least likely to trigger hemolytic reactions when transfused to recipients of any ABO/Rh type. This makes O− the universal donor for packed red blood cells. In contrast, AB+ is the universal recipient for RBCs. Note: for plasma, AB is the universal donor.

Question 30

Which vitamin is essential for blood clotting...?

Accepted Answer

Answer reason: Vitamin K is required for hepatic gamma-carboxylation of clotting factors II, VII, IX, and X, as well as proteins C and S, enabling them to bind calcium and function in the coagulation cascade. Deficiency leads to easy bruising and bleeding. Vitamin A is important for vision and epithelial integrity, and vitamin C is vital for collagen synthesis and wound healing, not for coagulation factor activation.

Question 31

Lack of blood is known as?

Accepted Answer

Answer reason: Anaemia is a hematologic condition defined by decreased red blood cell mass or hemoglobin concentration, colloquially referred to as a lack of blood. Insomnia is a sleep disorder and unrelated to blood volume or oxygen-carrying capacity. Angina is chest pain from myocardial ischemia, not a systemic deficiency of blood.

Question 32

Which of the following is a common finding in aplastic anemia?

Accepted Answer

Answer reason: Aplastic anemia is characterized by failure of hematopoietic stem cells, leading to markedly hypocellular bone marrow and decreased production of all three blood cell lines. This manifests as pancytopenia in the peripheral blood. Tumor infiltration is typical of myelophthisic processes, not aplastic anemia, and defective DNA synthesis describes megaloblastic anemia. A monoclonal disorder is not a defining feature of aplastic anemia.

Question 33

Blood clotting is controlled by?

Accepted Answer

Answer reason: Platelets are central to hemostasis: they adhere to injured endothelium, aggregate, and release mediators that activate the coagulation cascade, forming the initial platelet plug. Plasma contains clotting factors, but the process is primarily initiated and regulated locally by platelet activation at the injury site. RBCs and WBCs do not control coagulation.

Question 34

Leukemia is cancer of ?

Accepted Answer

Answer reason: Leukemia is a malignancy of hematopoietic cells characterized by uncontrolled proliferation of abnormal white blood cell precursors in the bone marrow. These blasts crowd out normal marrow, causing anemia and thrombocytopenia secondarily. The primary neoplastic process involves WBC lineages (myeloid or lymphoid), not RBCs, platelets, or plasma.

Question 35

Vitamin necessary for Blood clotting ____?

Accepted Answer

Answer reason: Vitamin K is required in the liver for gamma-carboxylation of clotting factors II, VII, IX, and X, and proteins C and S, enabling them to bind calcium and function in coagulation. Deficiency leads to impaired hemostasis and bleeding. Vitamin C is involved in collagen synthesis, and vitamin E is an antioxidant that can even impair platelet aggregation at high doses.

Question 36

The oxygen binding capacity of one gram of haemoglobin is-?

Accepted Answer

Answer reason: Fully saturated hemoglobin binds approximately 1.34 ml of oxygen per gram. This constant is used in the oxygen content equation: CaO2 = 1.34 × Hb × SaO2 + 0.003 × PaO2. At a typical Hb of 15 g/dL, this yields about 20 ml O2/dL carried by Hb, emphasizing that dissolved oxygen contributes minimally. Therefore, the correct value is 1.34 ml.

Question 37

Anaemia is caused in man due to the deficiency of?

Accepted Answer

Answer reason: Iron is essential for hemoglobin synthesis; deficiency leads to microcytic, hypochromic anemia and is the most common cause of anemia worldwide. Vitamin B12 and folic acid deficiencies can also cause anemia, but they produce megaloblastic patterns and are less common globally. Vitamin A deficiency is not a primary cause of anemia in typical exam contexts.

Question 38

Universal donors group?

Accepted Answer

Answer reason: Type O red blood cells lack A and B antigens, so they are least likely to be attacked by recipient anti-A or anti-B antibodies, making them the universal donor for RBC transfusion (particularly O negative when Rh is considered). In contrast, AB individuals have both antigens and are universal recipients for RBCs. Thus, among the choices, the universal donor group is O.

Question 39

Which of the following blood groups is called a universal donor?

Accepted Answer

Answer reason: Type O red blood cells lack A and B antigens on their surface, so recipients’ anti-A or anti-B antibodies are less likely to cause hemolysis. Therefore, type O is considered the universal donor in the ABO system. In practice, the safest universal donor for packed RBCs is O negative, accounting for the Rh factor.

Question 40

What is the lifespan of platelets?

Accepted Answer

Answer reason: Platelets typically circulate for about 7–10 days before being cleared by the reticuloendothelial system, mainly the spleen. This duration reflects normal platelet senescence and ongoing production from megakaryocytes. A 2–4 day span is pathologically short, while 10–12 or 12–20 days exceed normal physiologic survival.

Question 41

Which metal is found in human blood..?

Accepted Answer

Answer reason: Iron is the essential metal in hemoglobin within red blood cells. Each heme group contains a ferrous (Fe2+) iron atom that reversibly binds oxygen, enabling oxygen transport and giving blood its red color. Gold and silver are not physiological constituents of blood. Therefore, the correct metal found in human blood is iron.

Question 42

What is the lifespan of WBC?

Accepted Answer

Answer reason: White blood cell lifespan varies by subtype, but many standard references give an overall average of roughly 13–20 days. Granulocytes survive hours to a few days, while some lymphocytes can persist longer, but the commonly taught general range is around two to three weeks. Among the provided options, 12–20 days best matches this accepted range.

Question 43

Which of the following is responsible for carrying oxygen in the blood?

Accepted Answer

Answer reason: Haemoglobin within red blood cells binds oxygen via its heme iron and transports it from the lungs to tissues. Platelets function in blood clotting, not gas transport. White blood cells are immune cells. Plasma carries nutrients and proteins, and only a minimal amount of oxygen is dissolved in it, so it is not the primary oxygen carrier.

Question 44

Rouleaux formation is related to which of the cell/tissue?

Accepted Answer

Answer reason: Rouleaux formation refers to erythrocytes stacking like coins due to reduced zeta potential, typically from increased plasma proteins (e.g., fibrinogen, immunoglobulins). It is a phenomenon of red blood cells, not WBCs or platelets. This finding is associated with elevated ESR and conditions such as inflammation and multiple myeloma.

Question 45

Blood clot forms due to?

Accepted Answer

Answer reason: Platelets are central to hemostasis: they adhere to injured endothelium, become activated, and aggregate to form the primary hemostatic plug. Their granule contents amplify clotting and provide a surface for the coagulation cascade. Plasma contributes fibrinogen that is converted to fibrin to stabilize the platelet plug, but platelets initiate clot formation. WBCs and RBCs are not primary mediators of clot formation.

Question 46

Hemoglobin is found in?

Accepted Answer

Answer reason: Hemoglobin is the iron-containing oxygen-carrying protein concentrated within erythrocytes. RBCs are packed with hemoglobin, enabling transport of oxygen from the lungs to tissues and carbon dioxide back to the lungs. Leukocytes (WBCs) are immune cells and do not contain hemoglobin.

Question 47

Abnormal rise in number of R.B.C. is called?

Accepted Answer

Answer reason: An abnormal increase in red blood cell mass is termed polycythemia (erythrocytosis). Anaemia refers to a decrease in red blood cells or hemoglobin, not an increase. Leukemia is a malignant proliferation of white blood cells. Therefore, only polycythemia matches the stem.

Question 48

Name the blood group that has no antigen?

Accepted Answer

Answer reason: In the ABO blood group system, red blood cells carry A antigen (group A), B antigen (group B), both A and B antigens (group AB), or neither (group O). Therefore, group O lacks A and B antigens on the erythrocyte surface. This is why group O red cells can often be transfused broadly, although recipients’ plasma antibodies must still be considered.

Question 49

Which organ is called "blood bank" of body?

Accepted Answer

Answer reason: The spleen functions as a major blood reservoir, storing red blood cells and a significant proportion of the body's platelets. During hemorrhage or stress, it can contract to release stored blood into the circulation, helping maintain intravascular volume. It also filters aged or damaged erythrocytes as part of the reticuloendothelial system, reinforcing its role in blood homeostasis.

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