Immunity

Question 1

What are the two main types of immunity?

Answer 1

• Innate (non-specific)
• Adaptive (specific) immunity.

Question 2

What is the primary function of phagocytes in the immune response?

Answer 2

To engulf and digest pathogens through the process of phagocytosis.

Question 3

Define adaptive immunity.

Answer 3

Adaptive immunity is a specific immune response that involves the recognition of specific antigens and the production of targeted responses, including the activation of lymphocytes.

Question 4

What are the two types of lymphocytes involved in adaptive immunity?

Answer 4

B cells and T cells.

Question 5

How do B cells contribute to immunity?

Answer 5

B cells produce antibodies that bind to specific antigens, marking pathogens for destruction by other immune cells.

Question 6

What are the roles of helper T cells (Th cells) in the immune response?

Answer 6

Helper T cells activate other immune cells, including B cells to produce antibodies and cytotoxic T cells to destroy infected cells.

Question 7

What is the function of cytotoxic T cells

Answer 7

Cytotoxic T cells destroy infected or cancerous cells by inducing apoptosis (programmed cell death)

Question 8

Explain the concept of immunological memory.

Answer 8

Immunological memory refers to the ability of the adaptive immune system to remember a previous encounter with a pathogen, leading to a faster and stronger response upon re-exposure.

Question 9

What is an antigen?

Answer 9

An antigen is a molecule or molecular structure, often a protein, that is recognized by the immune system as foreign and can trigger an immune response.

Question 10

What is the role of antibodies in the immune system?

Answer 10

Antibodies bind to specific antigens, neutralizing pathogens or marking them for destruction by other immune cells.

Question 11

Describe the structure of an antibody.

Answer 11

An antibody is a Y-shaped molecule composed of four polypeptide chains—two heavy chains and two light chains—joined by disulfide bonds, with variable regions that bind to specific antigens.

Question 12

What is the major histocompatibility complex (MHC) ?

Answer 12

MHC molecules are cell surface proteins that present antigen fragments to T cells, playing a crucial role in the immune response.

Question 13

What is herd immunity?

Answer 13

Herd immunity occurs when a high percentage of the population is immune to a disease, either through vaccination or previous infection, reducing the spread and protecting those who are not immune.

Question 14

What are autoimmune diseases?

Answer 14

Autoimmune diseases occur when the immune system mistakenly attacks the body’s own cells, recognizing them as foreign.

Question 14

What is the difference between active and passive immunity?

Answer 14

Active immunity is when the body produces its own antibodies or T cells in response to an antigen, whereas passive immunity involves receiving pre-made antibodies from another source.

Question 14

How do vaccines work?

Answer 14

Vaccines stimulate the immune system to produce memory cells by exposing it to a harmless form of the pathogen or its antigens, providing immunity without causing disease.

Question 15

Provide an example of passive immunity

Answer 15

Newborns receiving antibodies from their mother’s breast milk or through the placenta.

Question 15

Name two examples of autoimmune diseases.

Answer 15

Rheumatoid arthritis and multiple sclerosis.

Question 16

What is the role of memory cells in the immune response?

Answer 16

Memory cells remain in the body after an initial infection and respond more rapidly and effectively upon re-exposure to the same pathogen.

Question 17

What is the significance of the primary and secondary immune responses?

Answer 17

The primary immune response occurs during the first exposure to an antigen and is slower, while the secondary immune response is faster and more robust due to the presence of memory cells.

Question 18

Define hypersensitivity reactions.

Answer 18

Hypersensitivity reactions are exaggerated immune responses to allergens, leading to conditions like allergies or anaphylaxis.

Question 19

What are monoclonal antibodies, and how are they used?

Answer 19

Monoclonal antibodies are identical antibodies produced by a single clone of B cells; they are used in treatments for diseases like cancer and in diagnostic tests.

Question 20

Explain the process of clonal selection in B cells.

Answer 20

Clonal selection is the process by which a B cell with a receptor specific to an antigen proliferates and differentiates into plasma cells that produce antibodies and memory cells.