Final answer:
A mouse with the mass-specific metabolic rate of an elephant would require less energy than a normal mouse, reflecting the relationship between animal size and energy consumption.
Step-by-step explanation:
If a mouse had the mass-specific metabolic rate of an elephant, it would require less energy than a normal mouse. The metabolic rate for a mouse is typically 890 mm³ O₂/g body mass/hr, whereas for an elephant it is 75 mm³ O₂/g body mass/hr. Since an elephant's metabolic rate is much lower, if a mouse had the metabolic rate of an elephant, it would be consuming and requiring much less oxygen per gram of body mass per hour compared to a normal mouse.
The difference between the rates illustrates how the size of an animal affects its energy consumption, with smaller animals usually having a higher metabolic rate than larger ones. This is related to their relatively larger surface area compared to their volume, which results in higher energy loss and therefore a need for a higher metabolic rate to maintain their internal environment.