Question 17N.2.HL.TZ0.01c
| Date | November 2017 | Marks available | [Maximum mark: 2] | Reference code | 17N.2.HL.TZ0.01c |
| Level | HL | Paper | 2 | Time zone | TZ0 |
| Command term | Explain | Question number | c | Adapted from | N/A |
Hypoxia is a condition in which tissues of the body are deprived of an adequate oxygen supply. A study was carried out in rats to examine the effects of continuing hypoxia on the structure of the diaphragm, and to determine whether nitric oxide is implicated in adaptation of the diaphragm to hypoxia. The diaphragm helps to supply oxygen to tissues and organs in the body by ventilating the lungs.
A group of 36 adult male rats were kept for 6 weeks in low oxygen while 36 adult male rats were kept in normal oxygen levels.
[Source: Reproduced with permission of the © ERS 2011. European Respiratory Journal June 2011, 37 (6) 1474–1481; DOI: 10.1183/09031936.00079810]
The graph shows the effect of hypoxia on the endurance of rats’ diaphragm muscle after 6 weeks. Endurance is the change in force measured as a percentage of the initial force.
[Source: Reproduced with permission of the © ERS 2011. European Respiratory Journal June 2011, 37 (6) 1474–1481; DOI: 10.1183/09031936.00079810]
Using the data presented in this question, explain the effect of hypoxia on the body.
[2]
a. diaphragm more endurance/stronger/generates more force for more ventilation/inspiration
b. right ventricle mass increases to pump more blood
c. erythrocyte percentage increases to transport oxygen
d. less growth/body mass which reduces oxygen demand
Reject “loss of body mass”
The physiological reason is required for each mark
[Max 2 Marks]
