MLPAO MLPAO Immunology and Serology

Question 1

Which immunoglobulin class is the first to be produced during a primary immune response?

Accepted Answer

IgM

Answer

IgG

Answer

IgA

Answer

IgE

Question 2

In the complement system, which pathway is activated by antigen-antibody complexes?

Accepted Answer

Classical pathway

Answer

Lectin pathway

Answer

Alternative pathway

Answer

Mannose-binding pathway

Question 3

A patient's serum is tested by ELISA for HIV antibodies. Which component is coated onto the microplate wells?

Accepted Answer

HIV antigens

Answer

Patient antibodies

Answer

Enzyme-conjugated secondary antibody

Answer

Complement proteins

Question 4

Which type of hypersensitivity reaction is responsible for anaphylaxis?

Accepted Answer

Type I (immediate)

Answer

Type II (cytotoxic)

Answer

Type III (immune complex)

Answer

Type IV (delayed)

Question 5

The prozone phenomenon in serology occurs when:

Accepted Answer

Antibody is in great excess, preventing lattice formation

Answer

Antigen concentration is too low to form any complexes

Answer

The temperature is too high for binding

Answer

Complement is depleted from the sample

Question 6

Which cell type is responsible for producing antibodies?

Accepted Answer

Plasma cells

Answer

Cytotoxic T lymphocytes

Answer

Natural killer cells

Answer

Macrophages

Question 7

A direct Coombs test (direct antiglobulin test) detects:

Accepted Answer

Antibodies bound to patient's red blood cells in vivo

Answer

Free antibodies in patient serum

Answer

Complement proteins in the patient's plasma

Answer

Antigens on donor red blood cells