ATI RN
Immune System Multiple Choice Questions Questions
Question 1 of 5
One striking feature of TCR interactions with peptide:MHC complexes is that amino acid residues in the MHC protein are as important to the TCR binding strength as are amino acid residues in the pathogen-derived peptide. This feature is in contrast to antigen recognition by antibodies, which is a direct interaction that is independent of other host proteins. Based on the different functions of T cells versus antibodies in the adaptive immune response, the fact that TCRs recognize components of both the MHC and the bound peptide exists to:
Correct Answer: D
Rationale: TCR-MHC recognition targets cell-associated antigens ; not just evasion or constraints , antibodies handle free antigens.
Question 2 of 5
The human lymphatic system consists of all of the following structures except the
Correct Answer: D
Rationale: The pancreas is not part of the lymphatic system, which includes thymus, tonsils, and spleen for immune functions.
Question 3 of 5
What type of cell helps to stimulate B cells to produce antibodies?
Correct Answer: C
Rationale: Helper T cells activate B cells via cytokines, enhancing antibody production, unlike plasma cells (antibody producers), cytotoxic T cells, or macrophages.
Question 4 of 5
Which complement component is involved in all complement pathways?
Correct Answer: B
Rationale: C3 is central to all pathways (classical, lectin, alternative), cleaved to initiate downstream effects, unlike C9 (MAC), C1q (classical), or C4 (classical/lectin).
Question 5 of 5
Complete the following sentence. The antigen binding site of an antibody is located......
Correct Answer: A
Rationale: The antigen-binding site is formed by variable regions of both heavy and light chains, creating specificity.