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Question 17N.2.HL.TZ0.01d.i

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Date November 2017 Marks available [Maximum mark: 2] Reference code 17N.2.HL.TZ0.01d.i
Level HL Paper 2 Time zone TZ0
Command term Analyse Question number d.i Adapted from N/A
d.i.
[Maximum mark: 2]
17N.2.HL.TZ0.01d.i

The sodium–potassium pump plays a role in muscle activity. Nitric oxide may have a role in the recovery of hypoxic muscles. The production of nitric oxide can be blocked with an inhibitor of the enzyme nitric oxide synthase. The graph shows the concentration of sodium–potassium pumps in the diaphragm of control and hypoxic rats without and with nitric oxide synthase inhibitor.

[Source: Reproduced with permission of the © ERS 2011. European Respiratory Journal June 2011, 37 (6) 1474–1481; DOI: 10.1183/09031936.00079810]

(d.i)

Analyse the graph to obtain two conclusions about the concentration of sodium–potassium pumps.

 

 

[2]

Markscheme

a. hypoxia increases the concentration of sodium–potassium pumps

b. nitric oxide needed for/stimulates «production of» sodium-potassium pumps

c. nitric oxide synthase inhibitor reduces the concentration of pumps
   OR
   concentration of pumps reduced by inhibiting nitric oxide production

Award up to [1] for a conclusion on lines labelled 1 and up to [1] for a conclusion on the lines labelled 2

[Max 2 Marks]

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