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

Lymph is modified blood that contains

  1. RBC and WBC

  2. RBC, WBC and protein

  3. WBC and all proteins

  4. all contents of blood except RBC and certain proteins
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Lymph is derived from interstitial fluid and contains water, ions, nutrients, WBCs (especially lymphocytes), but lacks RBCs and large plasma proteins like albumin which cannot easily leave capillaries. It's essentially blood plasma without RBCs and some proteins. Lymph is not a secretion of RBCs, nor does it contain RBCs.

Multiple choice

The three types of corpuscles in the human blood are

  1. erythrocytes, leucocytes and blood platelets

  2. erythrocytes, haemoglobin and plasma

  3. erythrocytes, leucocytes and haemoglobin

  4. erythrocytes, leucocytes and plasma
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The three types of blood corpuscles (formed elements) are erythrocytes (RBCs), leucocytes (WBCs), and thrombocytes (blood platelets). Hemoglobin is a protein within RBCs, not a separate cell type. Plasma is the liquid portion containing water, proteins, etc., not a corpuscle. This is fundamental blood cell classification.

Multiple choice

An antibody is a

  1. component of blood

  2. WBC which invades bacteria

  3. secretion of mammalian RBC

  4. molecule that superficially inactivates antigen
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Antibodies are glycoprotein molecules (immunoglobulins) produced by plasma cells (differentiated B lymphocytes) that bind specifically to antigens and neutralize them. They are not a blood component in themselves, not a WBC type (though they're produced by WBC derivatives), and not secreted by RBCs. Antibodies circulate in blood and lymph as part of humoral immunity.

Multiple choice

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

  1. sodium citrate

  2. sodium fluoride

  3. EDTA

  4. acid citrate destrose
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Sodium citrate is the most commonly used anticoagulant in blood banks because it binds calcium ions, which are essential for the coagulation cascade. It effectively prevents clotting while being safe for transfusion. EDTA is used primarily in diagnostic blood samples, not for storage.

Multiple choice

Which of the following statements is incorrect about the mechanism of blood clotting?

  1. Blood platelets burst when they come in contact with environment.

  2. Thromboplastin forms prothrombinase, which activates heparin.

  3. Thrombin acts as a proteolytic enzyme and converts fibrinogen into fibrin monomers.

  4. The fibrin monomers polymerise to form long threads.

  5. The clot seals the wound and the platelets entrapped in the clot release more thromboplastin.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Thromobplastin forms an enzyme prothrombinase that inactivates heparin andconverts inactive plasma protein; prothrombin into thrombin, which converts fibrinogen into fibrin monomers that polymerise to form long threads to clot the blood.

Multiple choice

Which of the following statements is not true about lymph?

  1. It is a colourless fluid and lacks erythrocytes.

  2. It contains many plasma proteins and high concentration of calcium and phosphorus.

  3. It consists of a fluid matrix in which white blood corpuscles are present.

  4. It mainly conveys materials from tissue cells into the blood.

  5. Its flow is very slow in the body.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Lymph contains fewer plasma proteins and a low concentration of calcium and phosphorus.