Immunology Quiz: B and T Cell Development and
Selection - Prof. Mumo (2026/2027)
Lymphocyte Biology & Central Tolerance | Key Domains: B Cell Development in Bone Marrow, T Cell
Development in the Thymus, Positive & Negative Selection Processes, Generation of Antigen
Receptor Diversity (VDJ Recombination), and Mechanisms of Central Tolerance (Clonal Deletion,
Receptor Editing, Anergy) | Expert-Aligned Structure | Multiple-Choice Quiz Format
Introduction
This structured Immunology Quiz for 2026/2027 provides 35 multiple-choice questions with
correct answers and rationales. It focuses on the intricate developmental pathways of B and T
lymphocytes, the molecular mechanisms that generate their diverse antigen receptors, and the
critical selection processes that shape a functional, self-tolerant adaptive immune system.
Quiz Structure:
• Lymphocyte Development Quiz: (35 MULTIPLE-CHOICE QUESTIONS)
Answer Format
All correct answers and developmental stages must appear in bold and cyan blue, accompanied by
concise rationales explaining the sequence of development (e.g., "Pro-B cell → Pre-B cell →
Immature B cell"), the anatomical location of a specific event (e.g., "Positive selection of T cells
occurs in the thymic cortex"), the molecular mechanism (e.g., "RAG enzymes mediate VDJ
recombination"), the purpose of a selection checkpoint (e.g., "Negative selection eliminates
self-reactive lymphocytes"), and why the alternative multiple-choice options contain factual
inaccuracies regarding lymphocyte biology or misorder the developmental sequence.
1. Where does B cell development primarily occur in adult humans?
A. Thymus
, B. Spleen
C. Bone marrow
D. Lymph nodes
B cell development occurs in the bone marrow from hematopoietic stem cells through defined stages
(pro-B, pre-B, immature B). The thymus (A) is for T cells; spleen (B) and lymph nodes (D) are
peripheral sites for mature lymphocyte activation, not development.
2. Which enzyme complex is essential for V(D)J recombination in developing lymphocytes?
A. DNA polymerase
B. Telomerase
C. RAG-1 and RAG-2
D. Reverse transcriptase
The recombination-activating genes RAG-1 and RAG-2 recognize recombination signal sequences (RSS)
and catalyze DNA cleavage for V(D)J recombination. DNA polymerase (A) replicates DNA; telomerase
(B) maintains chromosome ends; reverse transcriptase (D) converts RNA to DNA in retroviruses.
, 3. What is the first checkpoint in B cell development?
A. Expression of surface IgM
B. Successful rearrangement of the immunoglobulin heavy chain gene
C. Positive selection by self-MHC
D. Migration to the thymus
At the pro-B to pre-B transition, successful heavy chain (IgH) rearrangement leads to expression of the
μ heavy chain with surrogate light chain, forming the pre-BCR. This signals proliferation and
progression. Surface IgM (A) appears later; MHC selection (C) is for T cells; B cells do not go to the
thymus (D).
4. In which thymic region does positive selection of CD4⁺CD8⁺ (double-positive) T cells occur?
A. Medulla
B. Cortex
C. Capsule
D. Hassall’s corpuscles
Selection - Prof. Mumo (2026/2027)
Lymphocyte Biology & Central Tolerance | Key Domains: B Cell Development in Bone Marrow, T Cell
Development in the Thymus, Positive & Negative Selection Processes, Generation of Antigen
Receptor Diversity (VDJ Recombination), and Mechanisms of Central Tolerance (Clonal Deletion,
Receptor Editing, Anergy) | Expert-Aligned Structure | Multiple-Choice Quiz Format
Introduction
This structured Immunology Quiz for 2026/2027 provides 35 multiple-choice questions with
correct answers and rationales. It focuses on the intricate developmental pathways of B and T
lymphocytes, the molecular mechanisms that generate their diverse antigen receptors, and the
critical selection processes that shape a functional, self-tolerant adaptive immune system.
Quiz Structure:
• Lymphocyte Development Quiz: (35 MULTIPLE-CHOICE QUESTIONS)
Answer Format
All correct answers and developmental stages must appear in bold and cyan blue, accompanied by
concise rationales explaining the sequence of development (e.g., "Pro-B cell → Pre-B cell →
Immature B cell"), the anatomical location of a specific event (e.g., "Positive selection of T cells
occurs in the thymic cortex"), the molecular mechanism (e.g., "RAG enzymes mediate VDJ
recombination"), the purpose of a selection checkpoint (e.g., "Negative selection eliminates
self-reactive lymphocytes"), and why the alternative multiple-choice options contain factual
inaccuracies regarding lymphocyte biology or misorder the developmental sequence.
1. Where does B cell development primarily occur in adult humans?
A. Thymus
, B. Spleen
C. Bone marrow
D. Lymph nodes
B cell development occurs in the bone marrow from hematopoietic stem cells through defined stages
(pro-B, pre-B, immature B). The thymus (A) is for T cells; spleen (B) and lymph nodes (D) are
peripheral sites for mature lymphocyte activation, not development.
2. Which enzyme complex is essential for V(D)J recombination in developing lymphocytes?
A. DNA polymerase
B. Telomerase
C. RAG-1 and RAG-2
D. Reverse transcriptase
The recombination-activating genes RAG-1 and RAG-2 recognize recombination signal sequences (RSS)
and catalyze DNA cleavage for V(D)J recombination. DNA polymerase (A) replicates DNA; telomerase
(B) maintains chromosome ends; reverse transcriptase (D) converts RNA to DNA in retroviruses.
, 3. What is the first checkpoint in B cell development?
A. Expression of surface IgM
B. Successful rearrangement of the immunoglobulin heavy chain gene
C. Positive selection by self-MHC
D. Migration to the thymus
At the pro-B to pre-B transition, successful heavy chain (IgH) rearrangement leads to expression of the
μ heavy chain with surrogate light chain, forming the pre-BCR. This signals proliferation and
progression. Surface IgM (A) appears later; MHC selection (C) is for T cells; B cells do not go to the
thymus (D).
4. In which thymic region does positive selection of CD4⁺CD8⁺ (double-positive) T cells occur?
A. Medulla
B. Cortex
C. Capsule
D. Hassall’s corpuscles
