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Question 20N.3.HL.TZ0.c.i

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Date November 2020 Marks available [Maximum mark: 1] Reference code 20N.3.HL.TZ0.c.i
Level HL Paper 3 Time zone TZ0
Command term State Question number c.i Adapted from N/A
c.i.
[Maximum mark: 1]
20N.3.HL.TZ0.c.i

The human stomach kills pathogenic bacteria while allowing some benefi cial bacteria to survive. The diagram shows how mucus lining the stomach helps in this process.

[Source: Kavanaugh, D., O’Callaghan, J., Kilcoyne, M., Kane, M., Joshi, L. and Hickey, R.M., 2015. The intestinal glycome and
its modulation by diet and nutrition. Nutrition Reviews, 73(6), pp.359–375 by permission of Oxford University Press on behalf
of the International Life Sciences Institute. Translated and reprinted by permission of Oxford University Press on behalf of the
International Life Sciences Institute. Please visit: https://academic.oup.com/nutritionreviews/article/73/6/359/1845190.]

There are times when pathogenic bacteria infect the stomach, causing ulcers.

State a pathogenic bacterium that can cause stomach ulcers.

[1]

Markscheme

Helicobacter pylori/H. pylori

Examiners report

The majority of candidates could state Helicobacter pylori, some with minor distortion, but answers with other names were seen, including Escherichia coli and Vibrio cholerae.