ATI RN
Pediatric Immunization Practice Questions Questions
Question 1 of 5
The mutation on the X chromosome responsible for X-SCID is in the gene for a subunit of several cytokine receptors. Which of the following is true for boys affected with X-SCID at birth?
Correct Answer: A
Rationale: X-SCID (IL-2Rγ mutation) impairs T, B, and NK cell function.
Question 2 of 5
Lymphocyte passage (diapedesis or transmigration) occurs at the between adjacent endothelial cells then into the tissues.
Correct Answer: C
Rationale: Diapedesis occurs at adherens junctions between endothelial cells.
Question 3 of 5
Allelic exclusion creates monospecific B-cell receptors (BCRs). The result is these cells each secrete:
Correct Answer: D
Rationale: Allelic exclusion ensures each B cell produces antibodies with one specificity.
Question 4 of 5
In which of the following developmental stages of T cells are surface molecules CD4 and CD8 NOT expressed?
Correct Answer: A
Rationale: Double-negative (DN) cells lack both CD4 and CD8, unlike DP (both expressed) and SP (one expressed) stages.
Question 5 of 5
Activation of a T cell requires ___. Following activation, the T cell proliferates and differentiates into ___, then moves into peripheral tissues and other organs.
Correct Answer: D
Rationale: T-cell activation requires both MHC-antigen recognition and costimulation, leading to effector cell differentiation.