USA Biology Olympiad (USABO) Practice Exam

When comparing energy expenditures of a penguin and a python of equal size, which is true?

1. The energy expenditure of the python is greater

2. The energy expenditure is equal

3. The energy expenditure of the penguin is greater

4. The energy expenditure of the penguin is lower

The correct answer is: The energy expenditure of the penguin is greater

The energy expenditure of the penguin is greater than that of the python due to several physiological and behavioral factors. Penguins are warm-blooded (endothermic) animals, requiring a high metabolic rate to maintain their body temperature in cold environments, particularly in icy waters. This high metabolic rate leads to a greater energy demand. In contrast, pythons are cold-blooded (ectothermic) reptiles that depend on external heat sources to regulate their body temperature. Their metabolic processes slow down significantly in cooler environments, resulting in lower energy expenditures when compared to warm-blooded animals of the same size. Additionally, the active lifestyle of penguins, which includes swimming and diving to catch prey, requires substantial energy. This activity level also contributes to their higher overall energy expenditure compared to a python, which typically has a more sedentary lifestyle and relies on less energy for its maintenance processes. Therefore, when comparing the energy expenditures of these two animals, the penguin clearly has a greater energy expenditure due to its metabolic demands and active behaviors.