Question 21M.1A.SL.TZ2.37
| Date | May 2021 | Marks available | [Maximum mark: 1] | Reference code | 21M.1A.SL.TZ2.37 |
| Level | SL | Paper | 1A | Time zone | TZ2 |
| Command term | Question number | 37 | Adapted from | N/A |
The graph shows changes in the concentration of an antibody in the blood of an individual subjected to two separate infections at time X and time Y.
[Source: Illustration from Anatomy & Physiology, Connexions Web site. http://cnx.org/content/col11496/1.6/, Jun 19, 2013 OpenStax College © 1999-2021, Rice University. Except where otherwise noted, textbooks on this site are licensed under a Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/).]
What distinguishes the events occurring at Y from those occurring at X?
A. The individual was infected with different pathogens at X and Y.
B. Memory B cells are involved in antibody production at Y but not at X.
C. There is no clonal selection involved.
D. There are no T lymphocytes involved.
[1]
B
This question was the easiest on the paper for the candidates with 89 % selecting the correct response.
