Question 22N.1A.SL.TZ0.28
| Date | November 2022 | Marks available | [Maximum mark: 1] | Reference code | 22N.1A.SL.TZ0.28 |
| Level | SL | Paper | 1A | Time zone | TZ0 |
| Command term | Question number | 28 | Adapted from | N/A |
The graph shows the concentration of the lipid lecithin in the amniotic fluid surrounding the fetus during normal gestation. This lipid is produced in the lungs of the fetus and acts as a surfactant.
[Source: Gluck, L. and Kulovich, M., n.d. [Concentrations of phospholipids]. [graph online] Available at:
http://www.columbia.edu/itc/hs/medical/humandev/2004/Chpt12-LungDev.pdf [Accessed 28 October 2021].]
What problem may occur in a baby born before 34 weeks gestation?
A. Type I pneumocytes do not produce sufficient surfactant for lungs to inflate.
B. There are no type II pneumocytes.
C. The alveolar walls stick together.
D. The alveoli are too large.
[1]
C
This question concerned the production of a surfactant in the lungs. This question was the best discriminator on the paper. The most common incorrect response was A with candidates confusing the role of type I and type II pneumocytes.
