NEET Biology: coagulation of blood Practice Questions
15 free multiple-choice questions on coagulation of blood (Human Physiology) for NEET Biology, each with the correct answer and a step-by-step explanation. Attempt a question, then reveal the solution to check your reasoning.
Practice thousands more NEET questions in the app →Q1. Which of the following proteins plays the central role in converting fibrinogen into fibrin?
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Correct answer: A — Thrombin
Thrombin is the enzyme that catalyzes the conversion of fibrinogen (soluble) into fibrin (insoluble), which forms the clot.
Q2. The coagulation cascade involves two main pathways: the extrinsic pathway and the intrinsic pathway. Which pathway is primarily activated by tissue factor released from damaged tissue?
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Correct answer: A — Extrinsic pathway
The extrinsic pathway is initiated when tissue factor, released from damaged endothelial cells, binds to Factor VII, initiating the cascade.
Q3. Which blood component is critical for the physical process of plugging the initial vessel damage during coagulation?
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Correct answer: D — Platelets
Platelets (thrombocytes) adhere to the exposed collagen at the site of injury, forming the initial plug necessary for the clotting process.
Q4. The primary function of platelets in the initial phase of blood clotting is:
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Correct answer: A — Adhesion and aggregation
Platelets are crucial for initiating the process by adhering to the damaged site and aggregating to form a plug, which is the first step in clot formation.
Q5. Which plasma protein is the direct precursor that is converted into fibrin during blood coagulation?
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Correct answer: C — Fibrinogen
Fibrinogen is the soluble plasma protein that acts as the precursor and is cleaved by thrombin to form insoluble fibrin threads, which constitute the blood clot.
Q6. Which vitamin is essential for the proper synthesis of clotting factors in the blood?
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Correct answer: C — Vitamin K
Vitamin K is necessary for the activation of several clotting factors (II, VII, IX, and X) in the coagulation cascade.
Q7. Which enzyme is centrally involved in the coagulation cascade, responsible for converting fibrinogen into fibrin?
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Correct answer: C — Thrombin
Thrombin is the key enzyme in the coagulation cascade, catalyzing the conversion of fibrinogen to fibrin, the actual clot-forming protein.
Q8. The coagulation process is primarily regulated by a cascade of reactions involving various clotting factors. Which pathway is initiated by tissue factor (Factor III)?
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Correct answer: B — Extrinsic pathway
The Extrinsic pathway is initiated when tissue factor (released from damaged tissue) binds to Factor VII, leading to the activation of the cascade.
Q9. The final product formed during the coagulation process that provides structural stability to the blood clot is:
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Correct answer: B — Fibrin
Fibrin is the insoluble protein mesh that forms the stabilized fibrin network, which provides the final structural integrity to the blood clot.
Q10. Which factor in the coagulation cascade acts as the main enzyme that converts prothrombin to thrombin?
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Correct answer: D — Prothrombin
Prothrombin (Factor II) is converted into Thrombin (Factor IIa) by the action of Factor X, which is a key step in the activation cascade.
Q11. Which of the following statements best describes the role of the coagulation process?
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Correct answer: D — To prevent excessive bleeding
The coagulation process is fundamentally aimed at forming a stable clot to stop blood loss when a vessel is injured.
Q12. Which of the following is a crucial cofactor required for the activation of Factor X in the common pathway of coagulation?
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Correct answer: B — Thrombin
Thrombin, once generated, acts as a crucial cofactor, binding to Factor X to convert it into Factor Xa, which is an active enzyme in the cascade.
Q13. Which stage in the coagulation process involves the formation of a temporary, unstable clot that is later stabilized?
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Correct answer: A — Activation
The activation phase involves the sequential reaction of clotting factors leading to the formation of a stable clot (hemostasis).
Q14. The coagulation cascade primarily occurs within which specific part of the blood?
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Correct answer: D — Plasma
The coagulation cascade is a reaction involving various plasma proteins and clotting factors, primarily occurring within the plasma.
Q15. Which of the following is the first step in the formation of a blood clot after vascular injury?
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Correct answer: C — Activation of platelets
When a blood vessel is injured, platelets immediately adhere to the exposed collagen and to each other, initiating the clotting process.
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