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 animal behaviour ethology natural selection coordination in human beings- chemical control endocrine system in humans

The immunoglobulin abundant in colostrum is

  1. Ig G

  2. Ig M

  3. Ig A

  4. All of the above

  5. Ig E
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The yellow-coloured milk secreted by cattle soon after the birth of a calf is called as colustrum. Colostrum contains antibodies to protect the newborn against disease. Colostrum is known to contain immune cells (as lymphocytes) and many antibodies such as IgA, IgG and IgM. However, the most abundant immunoglobulin in colostrum is IgA.

Multiple choice biology option a: neurobiology and behaviour ethology animal behaviour natural selection

Colostrum, the first milk secretion of mammary gland of cow, is rich in immunoglobin

  1. IgE

  2. IgM

  3. IgA

  4. IgG
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Colostrum is produced in the initial secretions of the mammary gland following the birth of offspring. Colostrum is most commonly distinguished from whole milk because it contains high concentrations of immunoglobulins (Ig), otherwise known as antibodies. Antibodies are proteins which function to identify and destroy disease-causing pathogens in livestock. The primary immunoglobulin in cow colostrum and milk is IgG, whereas the primary immunoglobulin in human milk is IgA. Colostrum is also a vital source of growth factors and nutritional elements such as protein, fat, milk sugar, vitamins and minerals.

Multiple choice zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Which of the following helps in differentiation of lymphocytes?

  1. Cytosin

  2. Thymosin

  3. Cyclin

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

  • Thymosin hormones are typically produced by the thymus gland and trigger the creation of T-cells, which are used by the immune system to fight disease. 
  • Once puberty occurs in a human, a normal thymus has created the T-cells needed by the body and begins to shrink, eventually being replaced by fatty tissue. Hence, Thymosin helps in the differentiation of lymphocytes.
So, the correct answer is 'Thymosin'.

Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

The key component of hemostasis is 

  1. Feedback mechanism

  2. Complexity

  3. Cell content

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

Hemostasis is the process of blood coagulation or the formation of a clot to prevent blood loss when there is any injury. The main component of hemostasis is based on the positive feedback mechanism. There is activation of one coagulation factor which activates the other coagulation factor. This initiates a cascade mechanism which results in the formation of a proper clot. The mechanism stops or gets inhibited when there is formation of clot.  

Thus, the correct answer is option A. 

Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Positive feedback loop between cytokines and immune cells can cause

  1. Hypocytokinemia

  2. Hypercytokinemia

  3. Immune deficiency

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A positive feedback loop involving cytokines leads to an excessive and uncontrolled release of cytokines, a condition known as a cytokine storm or hypercytokinemia. Hypocytokinemia refers to a deficiency of cytokines, which is the opposite of this effect.

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

The process of blood clot formation within the circulatory system is

  1. Thrombosis

  2. Thrombocytes

  3. Thrombin

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

Thrombosis is the formation of a blood clot inside a blood vessel, obstructing the flow of the blood through the circulatory system.
Thrombocytes are also called 'platelets' and these are the blood cells, whose function is to stop bleeding.
Thrombin is the enzyme that converts fibrinogen to fibrin, and a reaction that leads to the formation of fibrin clot.
Thrombocytopenia is the disorder in which there is an abnormally low amount of platelets.
Thus, the correct answer is option (A).

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

Platelets are a source of ______________.

  1. Fibrinogen

  2. Calcium

  3. Thromboplastin

  4. Haemoglobin
Reveal answer Fill a bubble to check yourself
C 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 'Thromboplastin'.

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

Choose the correct answer from the four options given.
During blood coagulation, thromboplastin is released by?

  1. RBC

  2. Clumped platelets and damaged tissues

  3. Blood plasma

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

Blood coagulation is initiated by extrinsic and intrinsic pathways. Thromboplastin (Factor III) is released primarily by damaged blood vessel tissues and clumped platelets at the site of an injury to trigger the clotting cascade.

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

The anticoagulant most commonly used to store blood in the blood banks is

  1. Sodium nitrate

  2. Sodium fluoride

  3. EDTA

  4. Acid citrate dextrose
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Acid citrate dextrose solution (anticoagulant citrate dextrose solution) is a solution of citric acid, sodium citrate and dextrose in water. It is mainly used as an anticoagulant to preserve blood specimens required for tissue typing because it removes the calcium ion which plays an important role in blood clotting reaction.

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

Labile factor is associated with

  1. Blood coagulation

  2. Blood group

  3. Blood immunity

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

Coagulation (blood clotting) is a complex process that involves a positive feedback system. The factors involved are-
Factor I Fibrinogen
Factor II Prothrombin
Factor III Tissue Factor (Thromboplastin)
Factor IV Calcium
Factor V Labile factor, proaccelerin, Ac-globulin
Factor VII Stable factor, proconvertin
Factor VIII Antihaemophilic globulin (AHG), Antihaemphilic factor A 
Factor IX Christmas factor, plasma thromboplastin component
Factor X Stuart power factor
Factor XI Plasma thromboplastin antecedent
Factor XII Hageman factor
Factor XIII Fibrin stabilising factor
Vitamin K is essential for synthesis of factors II, VII, IX and X.
Their numbers represent the order in which they were discovered.

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

Which clotting factor has been rejected now?

  1. VIII

  2. VII

  3. VI

  4. V
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Clotting factor VIII is the antihemophilic factor while factor VII serves as an accelerator of serum prothrombin conversion. Clotting factor V is proaccelerin. Clotting factor VI was once considered to have clotting function but is now rejected. Thus, the correct answer is C. 

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

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.

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

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

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

  4. (iv), (i), (iii), (ii)
Reveal answer Fill a bubble to check yourself
D Correct answer
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.