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Question 20N.2.HL.TZ0.4b

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Date November 2020 Marks available [Maximum mark: 2] Reference code 20N.2.HL.TZ0.4b
Level HL Paper 2 Time zone TZ0
Command term Outline Question number b Adapted from N/A
b.
[Maximum mark: 2]
20N.2.HL.TZ0.4b
(b)

Outline the role of methanogenic archaeans in the movement of carbon in ecosystems.

[2]

Markscheme

a. methane produced from organic matter;

b. in anaerobic conditions;

c. methane diffuses into atmosphere/accumulates in ground/soil;

d. oxidized/converted to carbon dioxide (in atmosphere);

Examiners report

Answers were rather polarised, with candidates either understanding the role of methanogens or stumbling round in a mire of uncertainty. Although this may seem an obscure part of biology, methanogenesis is of great significance in terms of climate change.

Syllabus sections