Consider the energy budgets for a human, an elephant, a penguin, a mouse, and a snake. The          would have the highest total annual energy expenditure, and the          would have the highest energy expenditure per unit mass. a. elephant; mouse b. elephant; human c. mouse; snake d. penguin; mouse

Key Concepts

Metabolic Rate

Metabolic rate refers to the rate at which an organism converts food into energy. It is influenced by factors such as body size, activity level, and environmental conditions. Larger animals typically have a higher total metabolic rate due to their greater mass, but they often have a lower metabolic rate per unit mass compared to smaller animals, which tend to expend more energy relative to their size.

Allometric Scaling

Allometric scaling is a biological principle that describes how different biological variables change with the size of an organism. It explains why larger animals have lower metabolic rates per unit mass compared to smaller ones. This concept is crucial for understanding energy expenditure patterns across species of varying sizes, as it helps predict how energy needs scale with body mass.

Energy Expenditure

Energy expenditure is the total amount of energy used by an organism over a specific period, often measured annually. It encompasses all metabolic processes, including basal metabolic rate, physical activity, and thermoregulation. Different species exhibit varying energy expenditures based on their size, activity levels, and ecological niches, which is essential for comparing the energy budgets of the organisms mentioned in the question.