L9 QS BANK, BMS201 Past Paper PDF

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MedPrime

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New Mansoura University

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blood platelets hematology biology medical science

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This document contains multiple-choice questions (MCQs) about blood platelets, megakaryocytes, and their functions in blood clotting. The questions cover topics such as the normal range of blood platelets, their size, structure, and role in the bone marrow.

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Part One: Simple MCQs 1. What is the normal range for the number of blood platelets per microliter (μL) of blood? a) 50,000-100,000/ μL b) 100,000-200,000/ μL c) 150,000-400,000/ μL d) 400,000-600,000/ μL 2. Which of the following accurately describes the size of blood platelets? a) 0.5-1 μm in...

Part One: Simple MCQs 1. What is the normal range for the number of blood platelets per microliter (μL) of blood? a) 50,000-100,000/ μL b) 100,000-200,000/ μL c) 150,000-400,000/ μL d) 400,000-600,000/ μL 2. Which of the following accurately describes the size of blood platelets? a) 0.5-1 μm in diameter b) 1-2 μm in diameter c) 2-4 μm in diameter d) 4-6 μm in diameter 3. Blood platelets are derived from which of the following cell types? a) Megakaryocytes b) Erythrocytes c) Leukocytes d) Fibroblasts 4. Which of the following structures is responsible for maintaining the shape of a platelet? a) Dense granules b) Alpha granules c) Peripheral marginal bundle d) Open canalicular system 5. What is the main function of the open canalicular system in platelets? a) Storage of serotonin b) Production of energy c) Transport of factors with blood plasma d) Degradation of cellular components 6. Which type of granule in platelets contains serotonin? a) Alpha granules b) Dense granules c) Lysosomes d) Peroxisomes 7. Platelet-derived growth factor (PDGF) is found in which type of platelet granule? a) Alpha granules b) Dense granules c) Lysosomes d) Peroxisomes 8. What is the approximate size range of a megakaryocyte? a) 10-30 μm in diameter b) 30-150 μm in diameter c) 150-300 μm in diameter d) 300-500 μm in diameter 9. Where are megakaryocytes typically located in the bone marrow? a) Scattered throughout, but more adjacent to blood sinusoids b) Primarily in the central region of the bone marrow c) Exclusively within the bone marrow sinusoids d) Clustered around blood vessels 10. What are the invaginations of the cell membrane in mature megakaryocytes called? a) Pseudopodia b) Proplatelets c) Demarcation membranes d) Canalicular system Part Two: Complex MCQs 1. A patient presents with prolonged bleeding after a minor injury. Which of the following cellular abnormalities is most likely contributing to this condition? a) Decreased number of red blood cells b) Increased number of white blood cells c) Reduced platelet count d) Elevated fibrinogen levels 2. During the process of blood clotting, platelets adhere to the injured blood vessel wall. Which component of the platelet is primarily responsible for this adhesion? a) The cell coat (glycocalyx) b) Microtubules c) Mitochondria d) Lysosomes 3. A researcher is studying the role of platelets in wound healing. Which of the following platelet components is most likely to be the focus of their research? a) Serotonin b) ATP c) Platelet-derived growth factor (PDGF) d) Calcium ions 4. A blood smear shows abnormally large platelets. This observation could suggest a defect in which of the following processes? a) Platelet adhesion b) Platelet activation c) Platelet fragmentation from megakaryocytes d) Platelet granule formation 5. In a bone marrow biopsy, a pathologist observes a large cell with a multi-lobed nucleus located adjacent to a blood sinusoid. This cell is most likely a: a) Megakaryoblast b) Megakaryocyte c) Myeloblast d) Erythroblast 6. Which of the following statements best describes the relationship between proplatelets and blood platelets? a) Proplatelets are fragments of blood platelets b) Blood platelets are formed from the fragmentation of proplatelets c) Proplatelets and blood platelets are synonymous terms d) Proplatelets inhibit the formation of blood platelets 7. A mutation affects the formation of demarcation membranes in megakaryocytes. What is the most likely consequence of this mutation? a) Increased platelet production b) Decreased platelet production c) Enhanced platelet adhesion d) Impaired platelet activation 8. Which of the following events occurs during the final stage of platelet formation? a) Endomitosis in megakaryoblasts b) Granule formation in megakaryocytes c) Extension of proplatelets into sinusoid lumens d) Fusion of megakaryocytes 9. A patient has a genetic disorder that results in the absence of dense granules in their platelets. Which of the following functions is most likely to be impaired in this patient's platelets? a) Adhesion to injured blood vessels b) Release of clotting factors c) Formation of platelet plugs d) Phagocytosis of bacteria 10. Which of the following best explains why megakaryocytes are typically located near blood sinusoids in the bone marrow? a) To facilitate the uptake of nutrients b) To enable direct release of platelets into the bloodstream c) To interact with other hematopoietic cells d) To avoid being damaged by bone marrow stromal cells 11. A medical student is observing a bone marrow smear under a microscope. They identify a cell with a large, multi-lobed nucleus and abundant cytoplasm. Which of the following statements about this cell is most likely true? a) It is actively undergoing mitosis b) It is in the process of differentiating into a red blood cell c) It will give rise to multiple platelets d) It plays a role in immune defense 12. Which of the following cytoskeletal elements plays a crucial role in the formation of proplatelets? a) Microtubules b) Intermediate filaments c) Microfilaments d) All of the above 13. A researcher is investigating a novel drug that targets the open canalicular system in platelets. What is the most likely mechanism of action of this drug? a) Inhibition of platelet adhesion b) Prevention of platelet activation c) Interference with the release of platelet granules d) Disruption of platelet shape 14. Which of the following statements accurately reflects the role of the hyalomere in platelet function? a) It contains the majority of the platelet's organelles b) It is responsible for the platelet's contractile properties c) It houses the platelet's genetic material d) It plays a minor role in platelet function 15. A patient with a bleeding disorder is found to have a deficiency in a protein involved in platelet adhesion. This protein is most likely located in the: a) Hyalomere b) Granulomere c) Cell coat (glycocalyx) d) Demarcation membranes Answer Guide Part One 1. c 2. c 3. a 4. c 5. c 6. b 7. a 8. b 9. a 10. c Part Two 1. c 2. a 3. c 4. c 5. b 6. b 7. b 8. c 9. b 10. b 11. c 12. a 13. c 14. b 15. c Done

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