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

Which of the following statements regarding peritoneal macrophages is true?

  1. They are fixed macrophages.

  2. They are wandering macrophages.

  3. They are found in the bones.

  4. They are killer cells.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This is the correct option. Wandering macrophages are the macrophages that leave blood and migrate to an infected tissue. Peritoneal macrophages are wandering macrophages.

Multiple choice

Which of the following conditions occurs in immunodeficiency disease X-linked agammaglobulinemia?

  1. Normal number of B-cells with decreased IgG and IgA and increased IgM

  2. B-cells are present but with reduction in 2 or more isotypes

  3. Complete lack of antibodies

  4. Selective immunoglobulin A deficiency
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In X-linked agammaglobulinemia, B-cells are not generated. Due to this, antibodies are not formed and it manifests as a complete lack of antibodies in their bloodstream. It happens due to a mutation in X-chromosome.

Multiple choice

Autoimmune thrombocytopenic purpura (ITP) is characterised by

  1. an increase in platelet count

  2. a decrease in platelet count

  3. bone marrow abnormalities

  4. blister formation on the skin
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Autoimmune thrombocytopenic purpura is characterised by a decrease in platelet count. ITP is an autoimmune disease with antibodies detectable against several platelet surface antigens.

Multiple choice

Which of the following is not an action of adjuvants?

  1. They extend the presence of antigens in the blood.

  2. They activate macrophages and lymphocytes.

  3. They accelerate the division of immune cells.

  4. They support the production of cytokines.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Adjuvants do not accelerate the division of immune cells.

Multiple choice

Match the columns.

 
Phagocyte Function
1. NK cells a. Present antigens
2. Dendritic cells b. Anaphylaxis
3. Mast cells c. Attack and destroy tumor cells
4. Macrophages d. Scavengers
  1. 1. NK cells d. Scavengers
    2. Dendritic cells c. Attack and destroy tumor cells
    3. Mast cells a. Present antigens
    4. Macrophages b. Anaphylaxis
  2. 1. NK cells c. Attack and destroy tumor cells
    2. Dendritic cells a. Present antigens
    3. Mast cells b. Anaphylaxis
    4. Macrophages d. Scavengers
  3. 1. NK cells b. Anaphylaxis
    2. Dendritic cells d. Scavengers
    3. Mast cells a. Present antigens
    4. Macrophages c. Attack and destroy tumor cells
  4. 1. NK cells d. Scavengers
    2. Dendritic cells b. Anaphylaxis
    3. Mast cells c. Attack and destroy tumor cells
    4. Macrophages a. Present antigens
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This is the correct match. Natural killer (NK cells) cells are leukocytes that attack and destroy tumor cells. Dendritic cells present antigens to T-cells. Mast cells are most often associated with allergy and anaphylaxis. Macrophages act as scavengers, ridding the body of worn-out cells and other debris.

Multiple choice

Protection against various microorganisms like bacteria, viruses, etc. inside the living cells is provided by which among the following components of the immune system?

  1. T-cells

  2. Antibodies

  3. C3b

  4. C1q

  5. Membrane-attack complex
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

T-lymphocytes are specialised for recognising peptides derived from intracellular infectious agents which are exhibited on the surface of an infected cell together with MHC class I & II molecules.

Multiple choice

Which among the following is required for transferring specific immunity to M. tuberculosis in mice?

  1. B-cells

  2. T-cells

  3. Macrophages

  4. Neutrophils

  5. IgG
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

T-cells are important for immunity to M. tuberculosis through the provision of Th1 cytokines such as IFN-gamma to activate macrophages containing the bacilli and perhaps also the participation of cytotoxic T-cells. The latter may kill macrophages which cannot be rescued by cytokines thereby releasing the bacteria to be taken up by fresh young macrophages which can be activated to become killers.

Multiple choice

The HIV nef protein affects antigen presentation by

  1. causing MHC class I endocytosis

  2. containing glycine-alanine repeats which inhibit proteasome-mediated processing of the virus

  3. preventing peptide binding to TAP

  4. preventing peptide transport through the TAP pore

  5. competing for peptide binding to the MHC class I heavy chain

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

It thereby prevents effective presentation of antigen peptides to the T-cell receptor.