| Date | May 2011 | Marks available | 3 | Reference code | 11M.3.SL.TZ2.1 |
| Level | Standard level | Paper | Paper 3 | Time zone | Time zone 2 |
| Command term | Compare | Question number | 1 | Adapted from | N/A |
Question
In Australia, a study was undertaken among women to determine the vitamin D levels in their blood. Levels of vitamin D were categorized as sufficient, insufficient and deficient to determine how prevalent each category was. Three locations at three different latitudes and four different seasons were used. A data summary is shown in the graphs below.
Identify the season when the women are least likely to suffer from vitamin D deficiency.
Using the data from all four seasons, identify the two locations where the patterns of vitamin D are most similar.
Determine what percentage of women in Geelong have insufficient vitamin D levels in winter.
Compare the deficiency levels of vitamin D at all three locations.
Location and season were found to account for only a small part of the deficiencies. Suggest, with reasons, how the behaviours of different people could influence the levels of vitamin D in their blood.
Markscheme
summer
Geelong and (Southeast) Queensland (both needed)
(40 −8) = 32% (accept answers in the range of 31 % to 33 %)
similarity:
none of the locations are deficient in Summer;
Geelong and (Southeast) Queensland have similar prevalence/levels of deficiency at all times of the year;
difference:
only Tasmania shows a deficiency in autumn;
Tasmania shows the highest prevalence of deficiency;
(Southeast) Queensland shows less prevalence/levels of deficiency overall;
To award [3], answers must address at least one similarity and one difference.
diets rich in vitamin D could raise vitamin D levels; (vice versa)
use of sunscreen/staying out of the sun/hats/clothing can reduce the production of vitamin D by the skin; (vice versa)
use of dietary supplements containing vitamin D can reduce deficiency levels;
Examiners report
N/A
N/A
N/A
The data in A1 was well understood by most candidates who were able to compare the data in A1 (b).
The data in A1 was well understood by most candidates who were able to compare the data in A1 (b) and suggest behaviours to influence their levels of vitamin D. Many candidates gave only one behaviour, thereby denying themselves the opportunity for a second mark. Most explained that people could expose themselves to more or less sunlight but few discussed dietary supplements.
