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Date November 2017 Marks available 1 Reference code 17N.3.SL.TZ0.12
Level Standard level Paper Paper 3 Time zone TZ0
Command term Calculate Question number 12 Adapted from N/A

Question

Calculate the energy loss due to respiration in primary consumers in kJ m–2 y–1.

[1]
a.

Outline why a year is more suitable than a month for the measurement of energy flow.

[1]
b.

Explain how pesticides may undergo biomagnification in the lake.

[2]
c.

Markscheme

190

a.

accounts for different productivity at different times of year/seasonal variations

OR

more data collected

OR

to increase reliability

OR

trends over time more easily detected

b.

a. the increase in concentration of the pesticide at higher trophic levels

b. taken in by organisms low in the food chain

c. cannot be excreted so remains in tissues

    OR

    accumulates as more organisms from lower levels are eaten

d. pesticides do not degrade/degrade very slowly

[Max 2 Marks]

c.

Examiners report

[N/A]
a.
[N/A]
b.
[N/A]
c.

Syllabus sections

Option C: Ecology and conservation » Option C: Ecology and conservation (Core topics) » C.2 Communities and ecosystems
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