| Date | May 2011 | Marks available | 1 | Reference code | 11M.1.SL.TZ1.28 |
| Level | Standard level | Paper | Paper 1 | Time zone | Time zone 1 |
| Command term | Question number | 28 | Adapted from | N/A |
Question
What normally prevents the membranes of the alveoli from sticking together during expiration?
A. The thickness of the single-cell layer of alveoli membranes
B. The secretion of fluids in the inner surface of the alveoli
C. The pressure within the thoracic cavity
D. The dense net of capillaries covering the alveoli
Markscheme
B
Examiners report
Some comments on the G2 forms implied that this was an unfair question. Most candidates did pick the right answer of B, although many were distracted by D, which is not an appropriate response. It was accepted that the stem of the question was not in alignment with the assessment statement, and so perhaps a little too much was asked of the candidates, but at the same time, it was felt that the question was not unfair.
