Biology Test Immunology 2

Question 1

Which type of hypersensitivity reaction involves IgE-mediated mast cell degranulation?

Accepted Answer

Type I

Answer

Type I hypersensitivity (immediate hypersensitivity) involves IgE antibodies bound to mast cells, which degranulate upon allergen re-exposure.

Question 2

What is the primary function of regulatory T cells (Tregs)?

Accepted Answer

Suppress immune responses to prevent autoimmunity

Answer

Regulatory T cells suppress excessive immune responses and maintain self-tolerance, preventing autoimmune diseases.

Question 3

Which complement pathway is activated by mannose-binding lectin (MBL)?

Accepted Answer

Lectin pathway

Answer

The lectin pathway is activated when mannose-binding lectin recognizes mannose residues on microbial surfaces.

Question 4

During an immune response, affinity maturation occurs in which structure?

Accepted Answer

Germinal centers of lymph nodes

Answer

Affinity maturation occurs in germinal centers where B cells undergo somatic hypermutation and selection for higher-affinity antibodies.

Question 5

Which molecule serves as a co-receptor for CD4+ T cells during antigen recognition?

Accepted Answer

MHC class II

Answer

CD4 binds to MHC class II molecules on antigen-presenting cells, stabilizing the interaction between the T cell receptor and the antigen-MHC complex.

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