Question 19M.3.HL.TZ2.21
| Date | May 2019 | Marks available | [Maximum mark: 6] | Reference code | 19M.3.HL.TZ2.21 |
| Level | HL | Paper | 3 | Time zone | TZ2 |
| Command term | Compare and contrast, Identify, Outline, Suggest | Question number | 21 | Adapted from | N/A |
Australia is in the Southern Hemisphere so December to February are summer months and June to August are winter months. Data on vitamin D deficiency levels were collected throughout the year for the Australian National Health Measures Survey. This was then used to analyse the seasonal effects of vitamin D deficiency. Vitamin D deficiency levels for those who had their blood samples taken in summer were compared with those who had them taken in winter. The maps show the vitamin D deficiency by state between 2011 and 2012.
[Source: www.abs.gov.au/ausstats/[email protected]/Lookup/4364.0.55.006Chapter2002011-12]
Identify which state had the smallest seasonal change in vitamin D levels.
[1]
Northern Territory ✔
The vast majority identified correctly Northern Territory, but some answered Queensland, which, although having a smaller value in summer, had a greater seasonal change.
Suggest one reason why people in Victoria show such a large seasonal change in vitamin D levels.
[1]
less sun in winter than in summer
OR
colder in winter so cover up/indoors more
OR
skin has more exposure to sun in summer ✔
Accept other valid suggestions.
Accept vice versa.
Most could provide a valid reason for a large seasonal change in Victoria implying a decrease in sun exposure; some answers were nevertheless unclear or irrelevant.
Outline one effect of lack of vitamin D.
[2]
a. «lack of vitamin D results in» calcium «ions» not absorbed from gut in sufficient quantities ✔
b. calcium salts not deposited or reabsorbed
OR
affects bone mineralization ✔
c. bones become softened/weakened ✔
d. can cause rickets «in children»/osteomalacia «in adults» ✔
The vast majority could list one effect of the lack of vitamin D, but it was more difficult for some to also include a cause in their outline.
Vitamins and minerals are both essential nutrients. Compare and contrast vitamins and dietary minerals.
[2]
Not necessary to present answer in a table.
Accept other valid similarities and/or differences.
Award marks for complete lines only.
An important number could provide a complete answer but the similarities and differences between vitamins and minerals are unclear for many; too many stated differences of different nature between the two.