Biology

Human Immunity and Blood

2,096 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

Leukopenia is the condition when

  1. bone marrow is destroyed

  2. the total number of lymphocytes decreases from 2% to 0.5%

  3. the total number of leukocytes increases above 6,000 per cubic mm

  4. the total number of leukocytes decreases below 5000 per cubic mm
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Leukopenia is the condition when the total number of leukocytes decreases below 5000 per cubic mm. Leukopenia can be identified with a complete blood count..

Multiple choice

Clumping of RBC may occur when the blood of one person is mixed with the serum or blood of another person. This is due to

  1. antigen-antibody reaction

  2. antitoxin-antibody reaction

  3. antitoxin-antigen reaction

  4. antibody-antibody reaction
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Option (1) is the correct answer.  Antigen-antibody reaction is a specific chemical interaction between antibodies produced by B cells of the white blood cells and antigens during immune reaction.

Multiple choice

The blood does not clot because of

  1. scarcity of thrombocytes

  2. scarcity of RBCs

  3. scarcity of WBCs

  4. abundance of WBCs
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Thrombocytes are the blood cells whose function is to stop bleeding.

Multiple choice

Which of the following does not apply to innate immune mechanisms?

  1. All cells of the immune system originates in the marrow cavity

  2. Absence of specificity

  3. Activation by a stimulus

  4. Involvement of multiple cell types

  5. First line of defense of the body
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

All cells of the immune system originates in the bone marrow and they include myeloid (neutrophils, basophils, eosinpophils, macrophages and dendritic cells) and lymphoid (B lymphocyte, T lymphocyte and Natural Killer) cells which differentiate along distinct pathways.

Multiple choice

Which of the following conditions characterises the germinal centers found in the cortical region of lymph nodes and the peripheral region of splenic periarteriolar lymphatic tissues of human body?

  1. Acts as the sites of NK cell differentiation in the body.

  2. Evokes an framework that on antigenic stimulation accomodates large populations of B lymphocytes and plasma cells.

  3. Provides stem cells and thus governs hematopoiesis.

  4. Governs the development of immature B and T cells.

  5. Participates in the removal of destroyed RBCs from the circulation.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

It is the correct statement as on antigenic stimulation, the germinal centers accomodates large populations of B lymphocytes undergoing mitosis and plasma cells secreting antibodies.

Multiple choice

The defective type of haemoglobin in sickle cell anaemia has _________ red–blood corpuscles.

  1. sickle – shaped

  2. dead

  3. round – shaped

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

Sickle cell anaemia is a genetic disorder in which the haemoglobin is defective and not efficient in O2 transport. This defective haemoglobin distorts the shape of RBC in which it is stored and they look sickle-shaped. Hence, the name “sickle cell” is derived. Being sickle shaped, it is difficult for the RBCs to move more freely in the blood vessels and so supply of oxygen to different organs and cells become slow and hence, respiration and release of energy becomes low, thereby making us feel lethargic.