[Campbell Biology P.940] Which of the following statements accurately describes the relation... | Practice Question

Which of the following statements accurately describes the relationship between animal body size and metabolic rate, and its physiological consequences?

• A: Larger animals have a higher overall metabolic rate and a higher metabolic rate per gram of tissue compared to smaller animals.
• B: The energy cost per gram of tissue increases with body size, explaining why elephants have a higher BMR per kilogram than mice.
• C: While a whole elephant uses far more calories than a whole mouse, a mouse's tissue requires about 20 times more calories per gram than an elephant's, necessitating higher rates of oxygen delivery and a more rapid heart rate in smaller animals.
• D: Metabolic rate remains roughly proportional to body mass raised to the 3/4 power (m^(3/4)) for all organisms, meaning small and large animals have similar energy demands per unit mass.