Practice C3.2 Defense against disease with authentic IB Biology exam questions for both SL and HL students. This question bank mirrors Paper 1A, 1B, 2 structure, covering key topics like cell biology, genetics, and ecology. Get instant solutions, detailed explanations, and build exam confidence with questions in the style of IB examiners.
Paper
Level
Question 1
SLPaper 1A
Based on the image, which numbered step represents the antigen-specific selection of a B-lymphocyte before clonal expansion occurs?
Question 2
SLPaper 1A
A researcher injects a lab mouse with heat-killed bacteria. Within hours, phagocytes are actively engulfing debris, despite the bacteria being non-viable.
Which aspect of the immune response explains this reaction?
Question 3
SLPaper 1A
- What distinguishes the adaptive immune system from the innate?
Question 4
SLPaper 1A
Which of the following best describes the function of memory B-cells?
Question 5
SLPaper 1A
In untreated HIV infection, CD4+ helper T-cells decline gradually, increasing vulnerability to secondary infections.
Which process underlies this loss of immune function?
Question 6
SLPaper 1A
Which of the following explains the ineffectiveness of antibiotics against viruses?
Question 7
SLPaper 1A
COVID-19 vaccines contain mRNA coding for the viral spike protein. Population-level data shows a decline in severe illness and hospitalizations following vaccination.
Which statement best explains how data validates vaccine efficacy?
Question 8
SLPaper 1A
During a second exposure to the same pathogen, the body responds more rapidly and with greater intensity.
Which mechanism explains this faster response?
Question 9
SLPaper 1A
Where are antigens usually found?
Question 10
SLPaper 1A
What is the correct term for a disease-causing organism such as a virus or bacterium?