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Question 1
Incorrect
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The actions of thrombin result directly in the release of:
Your Answer: 3 pairs of polypeptides from each fibrinogen molecule
Correct Answer: Fibrin monomers
Explanation:Thrombin in turn acts as a serine protease that converts soluble fibrinogen into insoluble strands of fibrin, as well as catalysing many other coagulation-related reactions.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 2
Correct
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The structure of haemoglobin A in adults includes
Your Answer: Haem, globin polypeptide chains α and β
Explanation:Haemoglobin A (HbA), also known as adult haemoglobin or α2β2, is the most common human haemoglobin tetramer, comprising over 97% of the total red blood cell haemoglobin. It consists of two alpha chains and two beta chains.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 3
Correct
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Question 4
Correct
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Lymphoid stem cells give rise to the following cells:
Your Answer: T cells, b cells and natural killer cells
Explanation:T Cells, B Cells and NK Cells (and all other Innate lymphoid cells) are unique to the lymphocyte family, but dendritic cells are not. Dendritic cells of identical appearance but different markers are spread throughout the body, and come from either lymphoid and myeloid lineages.
Myeloid stem cells lead to myeloblasts, which evolve into macrophages, monocytes, neutrophils, basophils, and eosinophils.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 5
Correct
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Which of the following is a function of Vitamin C?
Your Answer: Hydroxylation of proline to hydroxyproline for collagen synthesis
Explanation:Vitamin C acts as an electron donor for eight different enzymes: Three enzymes (prolyl-3-hydroxylase, prolyl-4-hydroxylase, and lysyl hydroxylase) that are required for the hydroxylation of proline and lysine in the synthesis of collagen.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 6
Correct
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Platelets are stored in this body organ.
Your Answer: Spleen
Explanation:Megakaryocyte and platelet production is regulated by thrombopoietin. Each megakaryocyte produces between 1,000 and 3,000 platelets during its lifetime. An average of 1011 platelets are produced daily in a healthy adult. Reserve platelets are stored in the spleen, and are released when needed by splenic contraction induced by the sympathetic nervous system.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 7
Correct
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What is the average life span of red blood cells?
Your Answer: 4 months
Explanation:Approximately 2.4 million new erythrocytes are produced per second in human adults. The cells develop in the bone marrow and circulate for about 100–120 days (4 months) in the body before their components are recycled by macrophages.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 8
Correct
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Which of the following conditions is procoagulant?
Your Answer: Factor V Leiden
Explanation:Factor V Leiden is a genetic mutation of one of the clotting factors in the blood, Factor V. This mutation makes Factor V resistant to inactivation by activated Protein C, which normally helps to regulate clot formation. As a result, individuals with Factor V Leiden are at increased risk of developing abnormal blood clots (thrombophilia), making it a procoagulant condition.
The other conditions listed are associated with bleeding tendencies rather than increased clotting:
- Afibrinogenemia: A rare genetic disorder where there is a complete lack of fibrinogen, leading to bleeding problems.
- Hemophilia: A group of inherited bleeding disorders where blood does not clot properly due to the lack of sufficient blood-clotting proteins (factors VIII or IX).
- Hypothrombinemia: A condition characterized by low levels of prothrombin, leading to increased bleeding.
- Christmas disease (Hemophilia B): A form of hemophilia caused by a deficiency of factor IX, resulting in a bleeding tendency.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 9
Incorrect
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With regards to splenic micro-architecture which is not contained within the red pulp
Your Answer: Reticular fibers
Correct Answer: Malpighian corpuscles
Explanation:Red pulp is responsible for mechanical filtration of red blood cells and is composed of sinusoids, which are filled with blood, splenic cords of reticular fibers and a marginal zone bordering on white pulp. White pulp provides an active immune response through humoral and cell-mediated pathways. Composed of nodules, called Malpighian corpuscles. These are composed of: lymphoid follicles, rich in B-lymphocytes and periarteriolar lymphoid sheaths (PALS), rich in T-lymphocytes.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 10
Correct
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Where is the most erythropoietin produced?
Your Answer: Kidneys
Explanation:Erythropoietin is produced by interstitial fibroblasts in the kidney in close association with peritubular capillary and proximal convoluted tubule. It is also produced in perisinusoidal cells in the liver. While liver production predominates in the fetal and perinatal period, renal production is predominant during adulthood.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 11
Correct
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Which of the following foods do NOT contain high levels of folate?
Your Answer: Yellow vegetables
Explanation:Folate naturally occurs in a wide variety of foods, including vegetables (particularly dark green leafy vegetables), fruits and fruit juices, nuts, beans, peas, dairy products, poultry and meat, eggs, seafood, grains, and some beers. Avocado, beetroot, spinach, liver, yeast, asparagus, and Brussels sprouts are among the foods with the highest levels of folate
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This question is part of the following fields:
- Haematology
- Medicine
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Question 12
Incorrect
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Stem cell characteristics include the following except
Your Answer: Differentiation and proliferation into progenitor cells committed to one cell line
Correct Answer: Differentiation and proliferation into progenitor cells committed to multiple cell lines
Explanation:The classical definition of a stem cell requires that it possess two properties:Self-renewal: the ability to go through numerous cycles of cell division while maintaining the undifferentiated state.Potency: the capacity to differentiate into specialized cell types. In the strictest sense, this requires stem cells to be either totipotent or pluripotent to be able to give rise to any mature cell type
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This question is part of the following fields:
- Haematology
- Medicine
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Question 13
Incorrect
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Which one of the following is true about bone marrow?
Your Answer: Yellow marrow is mainly fat cells with scanty blood vessels and capillaries
Correct Answer: At birth the bone marrow is entirely red marrow and is converted to yellow marrow with age
Explanation:The two types of bone marrow are red marrow, which consists mainly of hematopoietic tissue, and yellow marrow, which is mainly made up of fat cells. Red blood cells, platelets, and most white blood cells arise in red marrow. Both types of bone marrow contain numerous blood vessels and capillaries. At birth, all bone marrow is red. With age, more and more of it is converted to the yellow type; only around half of adult bone marrow is red.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 14
Correct
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The process in which tissue thromboplastin activates factor VII is best known as:
Your Answer: The extrinsic pathway
Explanation:In the tissue factor pathway (extrinsic), following damage to the blood vessel, FVII leaves the circulation and comes into contact with tissue factor (TF) expressed on tissue-factor-bearing cells (stromal fibroblasts and leukocytes), forming an activated complex (TF-FVIIa).
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This question is part of the following fields:
- Haematology
- Medicine
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Question 15
Correct
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In adults, the major site of haematopoiesis is?
Your Answer: The axial skeleton
Explanation:Bone marrow is the flexible tissue in the interior of bones. In humans, red blood cells are produced by cores of bone marrow in the heads of long bones.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 16
Incorrect
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Which vitamin is found in NAD and NADP?
Your Answer: Vitamin B6
Correct Answer: Vitamin B3
Explanation:In organisms, NAD can be synthesized from simple building-blocks (de novo) from the amino acids tryptophan or aspartic acid. In an alternative fashion, more complex components of the coenzymes are taken up from food as the vitamin called niacin (vitamin B3)
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This question is part of the following fields:
- Haematology
- Medicine
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Question 17
Correct
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Which of the following conditions is associated with eosinophilia?
Your Answer: Ascaris
Explanation:Eosinophilia can be idiopathic (primary) or, more commonly, secondary to another disease. In the Western World, allergic or atopic diseases are the most common causes, especially those of the respiratory or integumentary systems. In the developing world, parasites are the most common cause e.g. Ascaris
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This question is part of the following fields:
- Haematology
- Medicine
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Question 18
Correct
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In the normal adult, haematopoiesis is present
Your Answer: Axial skeleton and proximal ends of long bones
Explanation:In children, haematopoiesis occurs in the marrow of the long bones such as the femur and tibia. In adults, it occurs mainly in the pelvis, cranium, vertebrae, and sternum.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 19
Correct
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90% of erythropoietin necessary for haemopoesis is produced by the kidneys, the remainder is formed in the?
Your Answer: Liver
Explanation:Erythropoietin is produced by interstitial fibroblasts in the kidney in close association with peritubular capillary and proximal convoluted tubule. It is also produced in perisinusoidal cells in the liver. While liver production predominates in the fetal and perinatal period, renal production is predominant during adulthood.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 20
Correct
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Regarding transportation of iron in the body, the process in which iron is transported from the enterocyte into the blood occurs using which transporter protein:
Your Answer: Ferroportin
Explanation:Divalent metal transporter 1 (DMT1) transport several divalent metals including iron across the enterocyte’s cell membrane into the cell. The cell can then release it into the body via the only known iron exporter in mammals, ferroportin.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 21
Correct
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Where is Vitamin B12 mainly stored in the body?
Your Answer: Liver
Explanation:The total amount of vitamin B12 stored in body is about 2–5 mg in adults. Around 50% of this is stored in the liver. Approximately 0.1% of this is lost per day by secretions into the gut, as not all these secretions are reabsorbed.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 22
Correct
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The following occurs as a result of 2,3 Bisphosphoglycerate binding to deoxyhaemoglobin
Your Answer: A reduction in deoxyhaemoglobin's affinity for oxygen
Explanation:2,3-BPG acts as a heteroallosteric effector of haemoglobin, lowering haemoglobin’s affinity for oxygen by binding preferentially to deoxyhaemoglobin. An increased concentration of BPG in red blood cells favours formation of the T, low-affinity state of haemoglobin and so the oxygen-binding curve will shift to the right.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 23
Correct
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Transport of Iron into enterocytes occurs via which membrane transporter?
Your Answer: Divalent metal transporter 1(dmt1)
Explanation:To be absorbed, dietary iron can be absorbed as part of a protein such as haem protein or iron must be in its ferrous Fe2+ form. A ferric reductase enzyme on the enterocytes’ brush border, duodenal cytochrome B (Dcytb), reduces ferric Fe3+ to Fe2+. A protein called divalent metal transporter 1 (DMT1), which can transport several divalent metals across the plasma membrane, then transports iron across the enterocyte’s cell membrane into the cell.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 24
Correct
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Where is Vitamin B 12 absorbed?
Your Answer: Terminal ileum
Explanation:Protein-bound vitamin B12 must be released from the proteins by the action of digestive proteases in both the stomach and small intestine. Gastric acid releases the vitamin from food particles; therefore antacid and acid-blocking medications (especially proton-pump inhibitors) may inhibit absorption of B12. B12 must be attached to Intrinsic Factor (IF) for it to be efficiently absorbed, as receptors on the enterocytes in the terminal ileum of the small bowel only recognize the B12-IF complex; in addition, intrinsic factor protects the vitamin from catabolism by intestinal bacteria.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 25
Correct
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Where is retinol mainly stored?
Your Answer: Liver
Explanation:Vitamin A is a group of unsaturated nutritional organic compounds that includes retinol, retinal, retinoic acid, and several provitamin A carotenoids (most notably beta-carotene). The liver stores a multitude of substances, including glucose (in the form of glycogen), vitamin A (1–2 years’ supply), vitamin D (1–4 months’ supply), vitamin B12 (3–5 years’ supply), vitamin K, iron, and copper.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 26
Correct
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What is the function of Activated protein C?
Your Answer: Inactivates factor Va
Explanation:Activated Protein C (APC) is a crucial protein in the regulation of blood coagulation. Its primary functions include:
- Inactivating Factor Va: APC inactivates Factor Va, which is a cofactor for the conversion of prothrombin to thrombin by Factor Xa. By inactivating Factor Va, APC reduces thrombin formation, thereby acting as an anticoagulant.
- Inactivating Factor VIIIa: APC also inactivates Factor VIIIa, another cofactor that assists Factor IXa in the conversion of Factor X to Factor Xa. This further contributes to its anticoagulant effect.
These actions help to regulate blood clotting and prevent excessive thrombosis.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 27
Correct
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One of the cells of the bone marrow that are responsible for forming the various forms of differentiated blood cells are called?
Your Answer: Hematopoietic stem cell
Explanation:Hematopoietic stem cells (HSCs) or hemocytoblasts are the stem cells that give rise to all the other blood cells through the process of haematopoiesis. They are derived from mesoderm and located in the red bone marrow, which is contained in the core of most bones.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 28
Correct
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All of the following are Vitamin K-dependent clotting factors except:
Your Answer: Factor XI
Explanation:Activated Vitamin K is used to gamma carboxylate (and thus activate) certain enzymes involved in coagulation: Factors II, VII, IX, X, and protein C and protein S. Inability to activate the clotting cascade via these factors leads to the bleeding symptoms
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This question is part of the following fields:
- Haematology
- Medicine
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Question 29
Correct
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Synthesis of haem for haemoglobin occurs in the?
Your Answer: Mitochondria of the red blood cells
Explanation:Haemoglobin (Hb) is synthesized in a complex series of steps. The haem part is synthesized in a series of steps in the mitochondria and the cytosol of immature red blood cells, while the globin protein parts are synthesized by ribosomes in the cytosol.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 30
Incorrect
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Which enzyme deficiency causes Beriberi?
Your Answer: Niacin
Correct Answer: Thiamine
Explanation:Beriberi refers to a cluster of symptoms caused primarily by thiamine (vitamin B1) deficiency. Symptoms of beriberi include weight loss, emotional disturbances, impaired sensory perception, weakness and pain in the limbs, and periods of irregular heart rate.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 31
Correct
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Question 32
Incorrect
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Question 33
Incorrect
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Which statement is correct about the clinical state of methemoglobinemia?
Your Answer: Methaemoglobin, present in the circulation in small quantities, can resemble cyanosis.
Correct Answer: May arise due to a hereditary deficiency of NADH.
Explanation:Methaemoglobin is a form of haemoglobin that contains ferric [Fe3+] iron and has a decreased ability to bind oxygen. Spontaneously formed methaemoglobin is normally reduced by protective enzyme systems, e.g., NADH methaemoglobin reductase, hence a deficiency of NADH may result in increased levels of methaemoglobin
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This question is part of the following fields:
- Haematology
- Medicine
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Question 34
Correct
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Where is intrinsic factor secreted?
Your Answer: Gastric parietal cells
Explanation:Intrinsic factor (IF), also known as gastric intrinsic factor (GIF), is a glycoprotein produced by the parietal cells of the stomach. It is necessary for the absorption of vitamin B12 (cobalamin) later on in the small intestine.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 35
Correct
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Which vitamin plays a major role in the metabolism of many amino acids?
Your Answer: Vitamin B6
Explanation:Vitamin B6 is part of the vitamin B group, and its active form, pyridoxal 5′-phosphate (PLP) serves as a coenzyme in many enzyme reactions in amino acid, glucose, and lipid metabolism.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 36
Correct
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Regarding Iron stores, which of the following contains the highest proportion of total body iron?
Your Answer: Haemoglobin
Explanation:Most well-nourished people in industrialized countries have 4 to 5 grams of iron in their bodies. Of this, about 2.5 g is contained in the haemoglobin needed to carry oxygen through the blood, and most of the rest (approximately 2 grams in adult men, and somewhat less in women of childbearing age) is contained in ferritin complexes that are present in all cells, but most common in bone marrow, liver, and spleen.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 37
Correct
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Question 38
Correct
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Why is tissue plasminogen activator (tPa) a valuable treatment used in myocardial infarction and stroke?
Your Answer: It forms plasmin from its inactive precursor
Explanation:tPA is a serine protease involved in the breakdown of blood clots. It functions by converting plasminogen, an inactive precursor, into plasmin, an active enzyme. Plasmin then degrades fibrin, the main protein component of blood clots, leading to clot dissolution. This mechanism is particularly valuable in the treatment of myocardial infarction (heart attack) and ischemic stroke, where timely dissolution of the clot can restore blood flow to affected tissues and reduce damage.
Therefore, the correct answer is:
- It forms plasmin from its inactive precursor
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This question is part of the following fields:
- Haematology
- Medicine
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Question 39
Correct
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Which of the following is true regarding platelets?
Your Answer: Normally have a half-life of about 8 days
Explanation:Platelets have no cell nucleus: they are fragments of cytoplasm that are derived from the megakaryocytes of the bone marrow, and then enter the circulation. They have a half life of 5-9 days.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 40
Correct
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Which of the following is a precursor to the tissue macrophage?
Your Answer: Monocyte
Explanation:Monocytes are a type of white blood cell, or leukocyte. They are the largest type of leukocyte and can differentiate into macrophages or dendritic cells.
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This question is part of the following fields:
- Haematology
- Medicine
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