| Criteria | Marks |
|---|
| • Clear distinction between primary and secondary response to a pathogen by the adaptive immune system<br>• Correctly annotates relevant features on the graph (vaccinations, responses including increased rate and concertation in secondary response and antibody residual)<br>• Annotations and description are linked | 5 |
| • As above, but minor errors or lacking detail<br>• Annotates main features on the graph | 4 |
| • Provides relevant information about primary and secondary response AND<br>• Annotates some features on the graph but incorrectly positioned or lacking detail | 3 |
| • Provides relevant information about primary and secondary response OR<br>• Annotates some features on the graph but incorrectly positioned or brief | 2 |
| • Some relevant information provided | 1 |
Sample answer:
When the adaptive immune system is exposed to a pathogen for the first time it triggers a primary response. The primary response to an infection involves the activation and secretion of antibodies from plasma cells and the differentiation of T cells. Differentiated memory cells remain but the number of effector cells decreases over time. Subsequence exposure, in this case through a second dose of the vaccination, the secondary response is faster and stronger due to the memory cells that remain from the primary response with antigen specificity. This elicits a greater output of antibodies for a longer period of time. Comments: Many people didn’t add enough aspects to the graph (even though they wrote about them in their response, the questions states annotate the graph to support your answer. Read carefully. It says primary and secondary vaccinations were given but it doesn’t say to annotate primary and secondary vaccinations. It says account for the features of the graph. The antibody structure (or action) does not change between first and second exposure. Many didn’t talk about the larger residual conc. of antibodies from secondary exposure. Some people wrote great explanations but didn’t interact with the stimulus enough, this place you in a 3 mark section. Range 2-5 Avg. 3.58
