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Question 1
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 2
Incorrect
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Which of the following is a function of Vitamin C?
Your Answer: Iron transport across the enterocytes
Correct 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 3
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 4
Incorrect
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One of the functions of the spleen with regards to red blood cells is:
Your Answer: To manufacture reticulocytes
Correct Answer: To filter and remove aged and abnormal red blood cells
Explanation:The spleen plays important roles in regard to red blood cells (also referred to as erythrocytes) and the immune system. It removes old red blood cells and holds a reserve of blood, which can be valuable in case of haemorrhagic shock, and also recycles iron. As a part of the mononuclear phagocyte system, it metabolizes haemoglobin removed from senescent erythrocytes. The globin portion of haemoglobin is degraded to its constitutive amino acids, and the haem portion is metabolized to bilirubin, which is removed in the liver.
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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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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 6
Incorrect
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Lymphoid stem cells give rise to the following cells:
Your Answer: T cells, b cells and monocytes
Correct 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 7
Incorrect
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Vitamin B12 is transported from the enterocytes to the bone marrow by which factor?
Your Answer: Intrinsic factor
Correct Answer: Transcobalamin II (TC IIi)
Explanation:B12 must be attached to 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. Once the IF/B12 complex is recognized by specialized ileal receptors, it is transported into the portal circulation. The vitamin is then transferred to transcobalamin II (TC-II/B12), which serves as the plasma transporter.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 8
Incorrect
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Which statement about antithrombin III is true?
Your Answer: Its activity is inhibited by heparin.
Correct Answer: It inhibits particularly factor II and X
Explanation:Antithrombin inactivates its physiological target enzymes, Thrombin (Factor II), Factor Xa and Factor IXa. ATIII binds to thrombin and then forms the thrombin-anti thrombin complex or TAT complex. This is a major natural pathway of anticoagulation. This binding of thrombin to AT is greatly enhanced in the presence of heparin.
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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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What is the main function of vitamin E?
Your Answer: It is a cofactor in the formation of mannose containing glycoproteins
Correct Answer: It is an antioxidant
Explanation:Vitamin E has many biological functions, the antioxidant function being the best known. Other functions include enzymatic activities, gene expression, and neurological function(s).
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This question is part of the following fields:
- Haematology
- Medicine
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Question 10
Incorrect
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All of the following are Vitamin K-dependent clotting factors except:
Your Answer: Factor II
Correct 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 11
Correct
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Which of the following foods contain Vitamin B 12?
Your Answer: Liver, meat
Explanation:No fungi, plants, nor animals (including humans) are capable of producing vitamin B12. Only bacteria and archaea have the enzymes needed for its synthesis. Proved food sources of B12 are animal products (meat, fish, dairy products).
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This question is part of the following fields:
- Haematology
- Medicine
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Question 12
Correct
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Iron absorption occurs primarily in which part of the GIT?
Your Answer: Duodenum
Explanation:Like most mineral nutrients, the majority of the iron absorbed from digested food or supplements is absorbed in the duodenum by enterocytes of the duodenal lining.
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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 vitamin plays a major role in the metabolism of many amino acids?
Your Answer: Vitamin B3
Correct 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 14
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 15
Correct
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What is the average life span of neutrophils?
Your Answer: 24 hours
Explanation:The average lifespan of inactivated human neutrophils in the circulation has been reported by different approaches to be between 5 and 90 hours.
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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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von Willebrand factor stabilises which clotting factor?
Your Answer: Factor VII
Correct Answer: Factor VIII
Explanation:Von Willebrand factor’s primary function is binding to other proteins, in particular factor VIII, and it is important in platelet adhesion to wound sites. It is not an enzyme and, thus, has no catalytic activity. Factor VIII degrades rapidly when not bound to vWF. Factor VIII is released from vWF by the action of thrombin.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 17
Incorrect
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Which of the following is matched correctly with regard to stem cells of the bone marrow?
Your Answer: None of the above
Correct Answer: Hemopoietic stem cells - basophils
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 give rise to both the myeloid and lymphoid lineages of blood cells. (Myeloid cells include monocytes, macrophages, neutrophils, basophils, eosinophils, erythrocytes, dendritic cells, and megakaryocytes or platelets. Lymphoid cells include T cells, B cells, and natural killer cells.)
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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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Which vitamin is found in NAD and NADP?
Your 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 19
Correct
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Inactive cellular marrow is called
Your Answer: Yellow marrow
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.
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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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In the clotting mechanism, activation of factor IX can occur through the direct actions of:
Your Answer: Factor VIIa & XIa
Explanation:Factor IX is processed to remove the signal peptide, glycosylated and then cleaved by factor XIa (of the contact pathway) or factor VIIa (of the tissue factor pathway). When activated into factor IXa, in the presence of Ca2+, membrane phospholipids, and a Factor VIII cofactor, it hydrolyses one arginine-isoleucine bond in factor X to form factor Xa. Factor IX is inhibited by antithrombin.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 21
Incorrect
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Choose the correct statement regarding the protein C/S system?
Your Answer: Protein C activates protein S.
Correct Answer: The protein C/S complex inactivates factor Va and VIIIa
Explanation:The best characterized function of Protein S is its role in the anti coagulation pathway, where it functions as a cofactor to Protein C in the inactivation of Factors Va and VIIIa.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 22
Incorrect
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Which one of the following is necessary to activate plasminogen to plasmin?
Your Answer: Α2-antiplasmin
Correct Answer: tPA
Explanation:In circulation, plasminogen adopts a closed, activation resistant conformation. Upon binding to clots, or to the cell surface, plasminogen adopts an open form that can be converted into active plasmin by a variety of enzymes, including tissue plasminogen activator (tPA), urokinase plasminogen activator (uPA), kallikrein, and factor XII (Hageman factor).
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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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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 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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Which of the following is a granulocyte?
Your Answer: Eosinophil
Explanation:Granulocytes are a category of white blood cells characterized by the presence of granules in their cytoplasm. There are three principal types of granulocytes, distinguished by their appearance under Wright’s stain:
- Basophil granulocytes
- Eosinophil granulocytes
- Neutrophil granulocytes
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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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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 27
Incorrect
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Platelets are stored in this body organ.
Your Answer: Liver
Correct 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 28
Correct
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The intrinsic pathway of coagulation is activated by which of the following?
Your Answer: Collagen fibers underlying the endothelium
Explanation:The contact activation (intrinsic) pathway begins with formation of the primary complex on collagen by high-molecular-weight kininogen (HMWK), prekallikrein, and FXII (Hageman factor).
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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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The haemostatic plug formation in response to injured blood vessel wall is stimulated by exposure of which substance to platelets?
Your Answer: Collagen
Explanation:When the endothelium is damaged, the normally isolated, underlying collagen is exposed to circulating platelets, which bind directly to collagen with collagen-specific glycoprotein Ia/IIa surface receptors. This adhesion is strengthened further by von Willebrand factor (vWF), which is released from the endothelium and from platelets.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 30
Incorrect
SESSION STATS - PERFORMANCE PER SPECIALTY
