Comprehensive Immunology Quiz — T Cell OmpathStudy

Continued from $1. Section 15: T Cell Development Question 1.1 Which of the following is the correct order of developmental stages for T cells? Choices: a) Double-positive (DP) then double-negative (DN) then single-positive (SP) b) Double-positive (DP) then single-positive (SP) then double-negative (DN) c) Double-negative (DN) then double-positive (DP) then single-positive (SP) d) Double-negative (DN) then single-positive (SP) then double-positive (DP) Correct Answer: C Question 1.2 In which of the following developmental stages of T cells are surface molecules CD4 and CD8 NOT expressed? Choices: a) DN cell b) DP cell c) SP cell d) Mature T cell Correct Answer: A Question 2.1 Where are single-positive (SP) cells found? Choices: a) Bone marrow b) Thymus subcapsular zone c) Thymus cortex d) Thymus medulla e) Periphery Correct Answer: D Question 2.2 Where are double-negative (DN) cells found? Choices: a) Bone marrow b) Thymus subcapsular zone c) Thymus cortex d) Thymus medulla e) Periphery Correct Answer: B --- Section: Immunologic Memory (Section 7) Question 1 : Which of the following is NOT true when comparing primary immune response to subsequent (secondary) immune response? a) Primary response takes 5-10 days b) Secondary response takes 1-3 days c) Primary response has IgM as the major antibody class d) Secondary response has IgH (IgA or IgE) as the major antibody class e) Primary response has a high affinity for antigen Answer : E Evaluation : Agree with provided answer. The primary response produces low-affinity antibodies due to lack of affinity maturation. Option D is misleading (IgH is not standard; secondary response is dominated by IgG, not IgA/IgE), but E is definitively false. Question 2.1 : Which of the following is a low affinity antibody? a) IgA b) IgE c) IgH d) IgM Answer : D Evaluation : Agree with provided answer. IgM has low intrinsic affinity (binding strength per binding site) in its monomeric form, though pentameric structure provides high avidity. Question 2.2 : Which of the following best describes the affinity of antibody secreted for effector B cells? a) High b) Low c) Increases during response d) Decreases during response Answer : C Evaluation : Agree with provided answer. Affinity maturation during the immune response increases antibody affinity in effector B cells (plasma cells). Question 2.3 : The response time to antigenic stimulation for memory B and T cells is described as , for naïve B and T cells is described as , and for effector B and T cells is described as . a) Slow; Fast; Responding b) Fast; Slow; Responding c) Responding; Slow; Fast d) Responding; Fast; Slow e) Slow; Slow; Slow f) Fast; Fast; Fast Answer : B Evaluation : Agree with provided answer. Memory cells respond fast (primed), naïve cells respond slowly (require activation), and effector cells are actively "responding." Question 2.4 : Expression of L-selectin (CD62L), the receptor that facilitates homing of peripheral lymph nodes, is for memory T cells, for naïve T cells, and for effector T cells. a) High; Low; Variable b) Low; High; Variable c) Variable; High; Low d) Variable; Low; High e) High; Variable; Low f) Low; Variable; High Answer : C Evaluation : Agree with provided answer. Memory T cells show variable expression (subtype-dependent), naïve T cells have high expression (for lymph node homing), and effector T cells have low expression (for migration to tissues). Question 3 : Which of the following is NOT true regarding apoptosis of target cells? a) Apoptosis is triggered by Fas-Fas interactions and the activation of Caspase b) The critical cascade step is the activation of Caspase-activatable DNase (CAD) c) bcl genes are apoptotic genes meant to shorten memory cell survival d) Apoptosis of memory cells would lead to decreased secondary response e) Lack of apoptosis would lead to long-term survival of memory cells Answer : C Evaluation : Agree with provided answer. Bcl genes include anti-apoptotic members (e.g., Bcl-2) that promote memory cell survival, not shorten it. Option C misrepresents Bcl genes as solely pro-apoptotic. --- Section: Review of Immune Physiology (Section 18) Question 1.1 : The route of antigen processing (cytosolic versus vesicle bound) determines whether an antigen is presented by MHC class II molecules to a TCR on a CD4+ helper (TH) cell, or by major histocompatibility complex (MHC) class I molecules to a TCR on a CD8+ cytotoxic T cell. a) True b) False Answer : A Evaluation : Agree with provided answer. Cytosolic antigens (endogenous) are presented via MHC I to CD8+ T cells; vesicle-bound antigens (exogenous) are presented via MHC II to CD4+ T cells. Question 1.2 : The processes of affinity maturation and class switching are used to generate a lower-affinity, less effective antibody molecule during the immune response. a) True b) False Answer : B Evaluation : Agree with provided answer. Affinity maturation increases antibody affinity; class switching changes isotype for effector fu