EduNinja
(a)

Fig. 8.3 shows a ground squirrel, Ictidomys tridecemlineatus.

Fig. 8.3

Fig. 8.3

In the winter, the ground squirrel curls into a spherical shape underground and sleeps for long periods. During this time, the ground squirrel switches between two states:
- torpor, when the body temperature is maintained at 10∘C10^{\circ} \mathrm{C}
- euthermia, when the body temperature is maintained at 37∘C37^{\circ} \mathrm{C}.

Scientists used the activity of succinate dehydrogenase to investigate the rate of respiration in the mitochondria of ground squirrels. Mitochondria were extracted from liver and muscle samples of ground squirrels. The rate of respiration was measured at different concentrations of succinate and at temperatures that corresponded to torpor ( 10∘C10^{\circ} \mathrm{C} ) and euthermia ( 37∘C37^{\circ} \mathrm{C} ).

The results are shown in Fig. 8.4.

Fig. 8.4

Fig. 8.4

[ 3 ]
(i)

Describe the trends shown in Fig. 8.4.

[ 3 ]
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