ATI RN
Lymphatic System Practice Questions Questions
Question 1 of 5
The extensive polymorphism of MHC genes in the population is thought to represent an evolutionary response to outflank the evasive strategies of pathogens. This polymorphism makes it difficult for pathogens to eliminate all potential MHC binding epitopes from their proteins. Based on this reasoning, it would seem advantageous for each individual to encode more than three different MHC class I and three different MHC class II genes per chromosome copy. If some individuals in the population had MHC loci that encoded 10 different MHC class I and 10 different MHC class II genes, the T cell repertoire in those individuals would likely be:
Correct Answer: C
Rationale: More MHC alleles reduce T-cell diversity via stricter thymic selection; not more diverse , rare pathogens , or just alloreactive .
Question 2 of 5
Which of the following choices best describes a plasma cell?
Correct Answer: B
Rationale: Plasma cells are differentiated B cells that produce antibodies, not T cells or persistent memory cells.
Question 3 of 5
The first vaccination provides immunity because
Correct Answer: C
Rationale: Vaccines stimulate B cells with antigens, producing plasma cells (antibodies) and memory cells for immunity, not inflammation, pre-made antibodies, or antibiotics.
Question 4 of 5
Select a characteristic of the adaptive immune response.
Correct Answer: B
Rationale: Adaptive immunity takes days to develop specificity, unlike innate (PAMPs) or T cell antibody secretion (B cells).
Question 5 of 5
Complete the following sentence. A feature which does not describe patients presenting with x-linked hyper IgM syndrome is.
Correct Answer: C
Rationale: X-linked hyper IgM patients lack CD40L, preventing switching, so only IgM is produced, not normal levels of all isotypes.