In the following passage, each numbered space can be filled with a biological term.
Pathogens possess specific molecules on their outer surface known as (1) ___________ which trigger an immune response. In response to these, B-lymphocytes differentiate into (2) ___________ cells that secrete (3) ___________, which are Y-shaped (4) ___________ constructed of four polypeptide chains. This cellular or humoral response is an example of (5) ___________ immunity. Vaccination campaigns aim to achieve (6) ___________ immunity, protecting unvaccinated individuals by significantly reducing transmission within the population.
Write the correct biological term beside each number from 1 to 6 that matches the space in the passage.
Influenza requires a new vaccine formulation to be developed and administered every year. Suggest one reason why.
Table 1 shows the action of two antimicrobial agents.
| Antimicrobial agent | Action of antimicrobial |
|---|---|
| Rifampicin | Inhibits bacterial RNA polymerase, preventing transcription of DNA. |
| Vancomycin | Inhibits the synthesis of peptidoglycan in cell walls. |
Using the information in Table 1, explain why each antimicrobial agent is not effective against the influenza virus.
14 exam-style questions on AQA A Level Biology Cell recognition and the immune system, covering Cell recognition and the immune system. Each one has a worked solution and a mark scheme showing where the marks go.