Tag: soldiers of defense

Questions Related to soldiers of defense

Read the statements given below and choose the correct sequence of events leading the formation of a blood clot.
(i) Calcium activates an enzyme.
(ii) Fibrin binds platelets to form a 'plug'.
(iii) Thrombin converts fibrinogen to fibrin.
(iv) Platelets and damaged cells release an activator.

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  1. (i), (ii), (iii), (iv)

  2. (ii), (i), (iii), (iv)

  3. (iii), (iv), (i), (ii)

  4. (iv), (i), (iii), (ii)

Show answer
Correct Option: D
Explanation:
The process of blood clotting starts with the release of thromboplastin from damaged cells and platelets. Thromboplastin converts plasma protein prothrombin into thrombin in the presence of calcium ions. Thrombin then converts soluble plasma protein fibrinogen into fibrin which binds platelets to form a clot. 
Therefore, the correct answer is option D. 

What happens when a clot occurs in an undamaged blood vessel?

biology soldiers of defense blood clotting and healing of wounds coagulation of blood blood clotting

  1. The person would bleed to death.

  2. A scab will form on the skin surface.

  3. Platelets stick to the edges of the cut and to one another, forming a plug.

  4. The flow of blood to tissues beyond the clot may be cut off.

Show answer
Correct Option: D
Explanation:

When a clot occurs in an undamaged blood vessel, It stops the flow of blood to the rest of the tissue beyond the clot as, the blood can't flow through the clot. It causes paralysis in most of the cases. 

Therefore, the correct answer is option D.

Which enzyme induces lysis of fibrinogen to fibrin during fibrinolysis?

biology soldiers of defense blood clotting and healing of wounds coagulation of blood blood clotting

  1. Plasmin

  2. Thrombin

  3. Fibrin

  4. Trypsin

Show answer
Correct Option: B
Explanation:

Blood-clotting proteins circulate in the blood plasma in an inactive form, poised to participate in blood coagulation upon tissue injury. Blood-clotting proteins generate thrombin, an enzyme that converts fibrinogen to fibrin, and a reaction that leads to the formation of a fibrin clot.

Therefore, the correct answer is option B.

In human, the prothrombin required for blood clotting is produced inside the

biology soldiers of defense blood clotting and healing of wounds coagulation of blood blood clotting

  1. Liver

  2. Blood

  3. Bone

  4. Spleen

Show answer
Correct Option: A
Explanation:

Prothrombin is a coagulation or clotting factor that is needed for the normal clotting of blood. A cascade of biochemical events leads to the formation of the final clot. In this cascade, prothrombin is a precursor to thrombin.
Prothrombin is produced in the liver and is modified in the presence of vitamin K.
Therefore, the correct answer is option A.

The component of blood which prevents its coagulation in the blood vessels is

biology soldiers of defense blood clotting and healing of wounds coagulation of blood blood clotting

  1. Haemoglobin

  2. Plasma

  3. Thrombin

  4. Heparin

Show answer
Correct Option: D
Explanation:
Heparin is considered as the natural anticoagulant of the body which prevents blood clotting in blood vessels. It prevents the formation of thrombin. 
Hence, correct answer is option D. 

Which of the following happens if platelets are absent in blood?

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  1. Severe bleeding in case of injury or cuts

  2. Body cannot form clots

  3. Thrombocytopenia

  4. All of the above

Show answer
Correct Option: D
Explanation:

Platelets are components of blood. They prevent bleeding by activating coagulation mechanisms hence contribute in wound healing. They play an important role in inflammatory and proliferative events. If the platelets are not present in the blood there will be continuous loss of blood by the blood vessels which may prove fatal.

Blood clotting can be prevented in a test tube by adding a little

biology soldiers of defense blood clotting and healing of wounds coagulation of blood blood clotting

  1. Sodium oxalate

  2. Sodium chloride

  3. Sodium hydroxide

  4. Ammonium chloride

Show answer
Correct Option: A
Explanation:

Sodium oxalate acts as an anticoagulant. Sodium oxalate inhibits blood coagulation by forming an insoluble complex with calcium because calcium is a cofactor that involves in the clotting process. Hence, option A is the correct answer.

Blood does not clot inside the blood vessels due to the presence of

biology soldiers of defense blood clotting and healing of wounds coagulation of blood blood clotting

  1. Heparin

  2. Fibrinogen

  3. Vitamin K

  4. Thrombin

Show answer
Correct Option: A
Explanation:
Liver produces an anticoagulant, hetero-polysaccharide called heparin which prevent clotting inside the blood vessels. Heparin is a highly sulfated glycosaminoglycan and is also used to form an inner anticoagulant surface on experimental and medical devices.
Fibrinogen is a glycoprotein that helps in the formation of blood clots.
Thrombin is a blood coagulation factor.
Thus, the correct answer is option A. 

Which of the following does not play a role in blood coagulation?

biology soldiers of defense blood clotting and healing of wounds coagulation of blood blood clotting

  1. Vitamin K

  2. Vitamin D

  3. Calcium ions

  4. Fibrinogen

Show answer
Correct Option: B
Explanation:

Fibrinogen is factor I and its source is liver. When fibrinogen is converted into fibrin by thrombin, it forms long strands, that compose the mesh network for clot formation.
Calcium is factor IV and its source is bone and absorption from food in gastrointestinal tract. It works with many clotting factors for activation of the other clotting factors.
Vitamin K is an essential factor to various protein enzymes, that are a part of coagulation cascade.
Vitamin D is found in fish and liver oil and is essential for absorption of calcium.
Thus, the correct answer is option B.

A drop of each of the following, is placed separately on four slides. Which of them will not coagulate?

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  1. Blood plasma

  2. Blood serum

  3. Sample from the thoracic duct of lymphatic system

  4. Whole blood from pulmonary vein

Show answer
Correct Option: B
Explanation:

Coagulation is the process by which the blood changes from a liquid to a gel-like form. Blood plasma will coagulate, as, it has clotting factors in it and fibrinogen protein.
Serum will not coagulate, as, it do not have any clotting factors and fibrinogen.
Lymph is more like blood plasma, so, contains clotting factors and will coagulate.
Whole blood obviously coagulate for containing the same above factors.
Thus, the correct answer is option (B).