Biology

Human Immunity and Blood

2,051 Questions

Human immunity and blood questions cover the physiological mechanisms protecting the body against diseases and the components of blood. Topics include blood groups, cell mediated immunity, monoclonal antibodies, and blood coagulation. These biology topics frequently appear in general science sections of competitive exams.

Blood groupsCell mediated immunityMonoclonal antibodiesBlood coagulationCancer immunology

Human Immunity and Blood Questions

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

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

  1. Liver

  2. Blood

  3. Bone

  4. Spleen
Reveal answer Fill a bubble to check yourself
A Correct answer
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.

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

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

  1. Severe bleeding in case of injury or cuts

  2. Body cannot form clots

  3. Thrombocytopenia

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

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

Blood clot is mainly due to

  1. Plasma and RBC

  2. Plasma and thrombocytes

  3. Heparin and corpuscles

  4. Fibrin and corpuscles
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The presence of calcium and other clotting factors, Factor X activates an enzyme called prothrombin activator. The enzyme prothrombin activator then converts plasma protein prothrombin into thrombin. Thrombin is the enzyme which in turn converts fibrinogen into fibrin. Polymerized fibrin together with platelets(corpuscles) forms a clot at the wound site. Hence blood clot is mainly due to fibrin and corpuscles.

So the correct answer is 'Fibrin and corpuscles'.

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

Thromboplastin required for blood clotting is produced by

  1. Platelets

  2. Erythrocytes

  3. Monocytes

  4. Lymphocytes
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Thromboplastin is a plasma protein aiding blood coagulation through catalyzing the conversion of prothrombin to thrombin. It is a complex enzyme that is found in brain, lung, and other tissues and especially in blood platelets and that functions in the conversion of prothrombin to thrombin in the clotting of blood—called also thrombokinase.


So, the correct answer is 'Platelets'.

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

The coagulation of blood occurs due to

  1. Destruction of erythrocytes.

  2. Destruction of leucocytes.

  3. Change of fibrinogen into fibrin.

  4. Formation of serum.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
The mechanism of blood clotting involves The presence of calcium and other clotting factors, Factor X activates an enzyme called prothrombin activator. The enzyme prothrombin activator then converts plasma protein prothrombin into thrombin. Thrombin is the enzyme which in turn converts fibrinogen into fibrin. Polymerized fibrin together with platelets forms a clot at the wound site. Hence The coagulation of blood occurs due to change of fibrinogen into fibrin.
So, the correct answer is 'Change of fibrinogen into fibrin'.
Multiple choice biology soldiers of defense blood clotting and healing of wounds coagulation of blood blood clotting

Thrombokinase is produced in

  1. RBC

  2. WBC

  3. Blood vessels

  4. Blood clotting
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Thrombokinase is also known as thromboplastin. It is a complex enzyme which aids in clotting of blood. It is present in platelets and some body tissues. When the platelets aggregate at the site of injury, thrombokinase is released from platelets and damaged tissues. Thrombokinase converts prothrombin into thrombin which acts as an enzyme and converts fibrinogen into fibrin threads. The fibrin threads form a clot at the site of injury. Hence thrombokinase is produced in blood clotting.

So, the correct answer is 'Blood clotting'

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

The factor which initiates intrinsic pathway of blood clotting and triggers cascade reaction is

  1. Antihaemophiliac factor (VIII)

  2. Christmas factor (IX)

  3. Stuart-Prower factor (X)

  4. Hageman's factor (XII).
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Hageman's factor (Factor XII) is the contact activation factor that initiates the intrinsic pathway of the blood coagulation cascade when it comes into contact with exposed collagen or other negatively charged surfaces.

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

Thrombokinase is associated with

  1. Elimination of area and other excretory products from the body

  2. Production of erythrocytes from the bone marrow

  3. Pulmonary and systemic circulation

  4. Cardiac cycle and its regulation

  5. Enzymatic reactions in coagulation of blood.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Thrombokinase (also known as thromboplastin) is an enzyme that plays a critical role in the coagulation cascade by converting prothrombin into thrombin. This process is essential for blood clotting.

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

Thrombokinase is associated with

  1. Ellimination of urea and other excreatory products from the body.

  2. Production of erythrocytes from the bone marrow.

  3. Pulmonary and systematic circulation.

  4. Cardiac cycle and its regulation

  5. Enzymatic reactions in coagulation of blood.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Thrombokinase is a substance present in platelets which are necessary for coagulation of blood. Thromboplastin helps in the conversion of prothrombin to thrombin in the presence of calcium which is the vital step in coagulation of blood.

Hence, the correct option is E.

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

Blood agglutination tests are used in

  1. Antigen antibody reaction

  2. Animal relations

  3. Immunity

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Blood agglutination tests are used in Antigen-antibody reactions. The clumping of particles is called as agglutination. Clumping occurs when an antigen is mixed with its corresponding antibody. When people are given blood transfusions of the wrong blood group, the antibodies react with the incorrectly transfused blood group and as a result, the erythrocytes clump up and stick together causing them to agglutinate 
So, the correct answer is 'Antigen-antibody reaction'.
Multiple choice evs communicable diseases infectious diseases - transmission and prevention infectious diseases and how to prevent them pathogen and their mode of transmission

An insect bite may result in inflammation of that spot.This is triggered by the alarm chemicals such as 

  1. Histamine and dopamine

  2. Histamine and kinins

  3. Interferons and opsonins

  4. Interferons and histones
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • Histamine is an organic nitrogenous compound which is involved in the inflammatory response and has a central role as a mediator of itching.  Histamine increases the permeability of the capillaries to white blood cells and some proteins at the site of inflammation.
  • Kinins are a group of substances formed in body tissue in response to injury or inflammation. They are polypeptides and cause vasodilation (increase blood flow) at the site of inflammation and smooth muscle contraction.
So, the correct answer is 'Histamine and Kinins'.
Multiple choice biology digestive system of human digestive glands liver pancreas

Bilirubin is the breakdown product of

  1. Haemoglobin

  2. RBC

  3. WBC

  4. Platelets
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The dead RBCs are metabolised in the spleen and liver and the heme is broken down into bilirubin which is a yellow coloured pigment.

So, the correct option is 'Haemoglobin'.

Multiple choice zoology control and coordination in living organisms control of blood glucose endocrine system and hormone hormones in human reproduction testes and ovary parts of the brain kidney

Role of thymus in human is chiefly concerned with 

  1. Reproduction

  2. Immunology

  3. Calcium balance

  4. Blood coagulation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The thymus gland is an integral part of immune system. It helps in the maturation of lymphocytes. The thymus serves a vital role in the training and development of T-lymphocytes or T-cells, an extremely important type of white blood cell. So, the correct answer is option B.

Multiple choice bio-chemistry digestion liver functions of the liver secretory organs

Kupffer cells of liver are

  1. Loose connective tissue

  2. Phagocytic cell

  3. Mast cell

  4. Fat cell
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Kupffer cells constitute 80-90% of the tissue macrophages present in the body. They are found in the lumen of the liver sinusoids. 

So, the correct answer is 'phagocytic cells '