Date | May 2019 | Marks available | 3 | Reference code | 19M.3.SL.TZ2.13 |
Level | Standard level | Paper | Paper 3 | Time zone | Time zone 2 |
Command term | Explain | Question number | 13 | Adapted from | N/A |
Question
The diagram shows the copper concentration (μg g–1) in the seaweed Porphyra umbilicalis collected along the shoreline in Arklow, Ireland.
[Source: reprinted by permission from Springer Nature: Helgoländer Meeresuntersuchungen,
Problems in the assessment of heavy-metal levels in estuaries and the formation of a pollution index,
D L Tomlinson, et al., 33, issue 1, pages 566–575. Copyright 1980]
Explain how the copper found in these seaweeds could affect the birds living in Arklow town.
Markscheme
a. seaweed close to the estuary/town has a higher concentration of copper ✔
b. birds feed on fish/seaweed that have accumulated copper ✔
c. copper accumulates in tissues of organisms/bioaccumulation ✔
d. copper accumulates at a rate faster than that at which it is lost by excretion ✔
e. copper concentration increases as trophic level increases ✔
f. biomagnification occurs ✔
Examiners report
Candidates were asked to explain how copper found in seaweeds could affect birds. The question was not always answered in a coherent manner, but it was easy to achieve marking points and most candidates scored well.