ATI RN
Immune System Multiple Choice Questions and Answers Questions
Question 1 of 5
What is the role of HLA-DM protein in MHC II antigen presentation?
Correct Answer: A
Rationale: HLA-DM edits peptides for MHC II by releasing CLIP ; transport roles (B, D) and invariant chain guidance are distinct.
Question 2 of 5
The lymphatic trunk that drains the upper limb is the
Correct Answer: C
Rationale: The subclavian trunk drains the upper limb; bronchomediastinal drains the chest, intestinal the gut, and jugular the head/neck.
Question 3 of 5
The skin and bodily secretions provide the first line of defense against infection. One response in this category that is common during upper respiratory virus infections is:
Correct Answer: C
Rationale: Mucus production traps pathogens in the respiratory tract as a first-line defense; antibodies and WBC infiltration are later, saliva is less specific.
Question 4 of 5
Opsonization of pathogens by both antibodies and complement proteins (C3b) leads to uptake and destruction of the pathogen by phagocytic cells that express both Fc receptors and complement receptors. Which of the following in Figure Q2.16 is the most efficient form of dual opsonization of the pathogen by antibody and C3b to maximize phagocytosis?
Correct Answer: A
Rationale: Assuming Q2.16 shows options, dual opsonization with IgG and C3b maximizes phagocytosis via Fc and complement receptors.
Question 5 of 5
The cellular distribution of MHC class I versus MHC class II molecules is quite different, with MHC class II molecules generally expressed on a very limited set of cell types. This is because:
Correct Answer: B
Rationale: MHC II on APCs (macrophages, B cells) allows CD4 T-cell help ; CD8 killing or DC focus aren't the reason.