Biology Multiple Choice Questions on “Human Health and Disease – Cell Mediated Immunity”.
1. The full form of CMI is __________
a) cell Medium Immunoglobulin
b) cell-Mediated Immunity
c) cyst Marked Infection
d) cellular Medium Infection
Answer: b
Clarification: The full form of CMI is Cell-Mediated Immunity. The immune system comprises of T- lymphocytes that defend the body against pathogens, cancers and foreign structures like tissue transplants.
2. Which of the following mediate the CMI?
a) T-lymphocytes
b) Red blood corpuscles
c) White Blood cells
d) B-lymphocytes
Answer: a
Clarification: T-lymphocytes mediate CMI. T-cells/T-lymphocytes are long-lived small cells which have 100,000 receptor sites on their surface for binding antigens. T-cells themselves do not secrete antibodies but help B-cells to produce them.
3. Which of the following is called as Competent lymphocytes?
a) B-lymphocytes
b) T-lymphocytes
c) C- lymphocytes
d) S-lymphocytes
Answer: b
Clarification: T-lymphocytes are called as Competent lymphocytes. The cells develop antigen specificity through the previous contact. T-lymphocytes respond to specific antigen by forming a clone of cells.
4. Number of lymphocytes present in a healthy human is ___________
a) 1 trillion
b) 1 million
c) 1 billion
d) 10 trillion
Answer: a
Clarification: Number of lymphocytes present in a healthy human is 1 trillion. Unusually high or low lymphocyte counts can be a sign of disease.
5. A person without thymus would not be able to reject a tissue transplant.
a) True
b) False
Answer: a
Clarification: Thymus is a lobed organ located near the heart and beneath the breast bone. It is the site where T-lymphocytes mature. T-cells are the specialized white blood cells which help to defend the body.
6. What is the life of the effector cells of the immune system?
a) A few weeks
b) A few days
c) A few months
d) A few years
Answer: b
Clarification: The life span of effector cells of the immune system is a few days only. Our body releases two types of cells-effector cells and memory cells, of which, effector cells are short-lived and are responsible for the primary response of our body.
7. Which of the following sets include all the types of T-cells?
a) Killer cells and Helper cells
b) Suppressor and Cytotoxic cells
c) Depressor cells, Helper cells and Memory cells
d) Killer cells, Helper cells, Suppressor cells and Memory cells.
Answer: d
Clarification: T-cells of our immune system gets differentiated into Killer or cytotoxic cells, Helper cells, Suppressor cells and Memory cells. Killer, Helper and Suppressor T-cells are also called as Effector cells.
8. Life span of T-cells __________
a) 4-5 hours
b) 4-5 days
c) 4-5 weeks
d) 4-5 years
Answer: d
Clarification: Life span of T-cells is around 4-5 years. The T-cells produced are relatively long-lived to compensate the less number of T-cells produced by thymus in the later years.
9. B-cells produce antibodies in response to the instruction received from _________
a) Killer T-cells
b) Suppressor T-cells
c) Memory Cells
d) Helper T-cells
Answer: d
Clarification: B-cells produce antibodies in response to the instruction received from Helper T-cells. Along with this, Helper T-cells also attract macrophages to the site of infection.
10. How can Organ transplantation rejection be prevented?
a) Immunosuppressant drugs
b) Depressant drugs
c) Interferons
d) New T-cells
Answer: a
Clarification: Our body produces a certain type of antibodies in response to the antigens. When an organ is transplanted, the body recognises the ‘non-self’ cells and starts attacking them. Therefore, Organ Transplantation rejection can be prevented by giving Immunosuppressant drugs so that the immune system gets suppressed and do not attack the ‘non-self’ cells.
11. Which of the following cells of the immune system are responsible for causing pores in the plasma membrane of antigens?
a) Helper T-cells
b) Killer T-cells
c) Suppressor T-cells
d) Memory cells
Answer: b
Clarification: Killer T-cells are responsible for producing pores in the plasma membrane of the antigens. The interaction of Killer T-cells with antigens will produce perforins to kill the infected cells.
12. What does T stand for in T-lymphocytes?
a) Tonsils
b) Thymus
c) Tissue
d) Thyroid
Answer: b
Clarification: The letter T in T-lymphocytes stands for Thymus. The thymus is a primary lymphoid organ which is responsible for differentiating T-lymphocytes into antigen sensitive lymphocytes.
13. Helper T-cells can be distinguished from killer T-cells by the presence of _________
a) CD-2 receptor
b) CD-3 receptor
c) CD-8 receptor
d) CD-4 receptor
Answer: d
Clarification: Helper T-cells can be distinguished from Killer T-cells by the presence of CD-4 receptor. CD-8 receptors are present in both Killer T-cells and Suppressor T-cells.
14. Which of the following cell surfaces do not have Major Histocompatibility complex?
a) Red Blood Corpuscles
b) White Blood Cells
c) Helper T-cells
d) Killer T-cells
Answer: a
Clarification: The cell surface of Red Blood Corpuscle does not have Major Histocompatibility Complex. This complex is responsible for displaying the peptide fragments of antigens to the appropriate T-cells of our immune system.
15. What is meant by Apoptosis?
a) Accidental Cell Death
b) Programmed Cell death
c) Accidental Cell division
d) Programmed Cell division
Answer: b
Clarification: Apoptosis has been derived from an Ancient Greek word meaning “falling off”. In biology, Apoptosis refers to a form of programmed cell death that occurs in multicellular organisms. It is used by the immune system to get rid of the virus-infected cells.