You are studying a large tropical reptile that has a high and relatively stable body temperature. How do you determine whether this animal is an endotherm or an ectotherm? a. You know from its high and stable body temperature that it must be an endotherm. b. You subject this reptile to various temperatures in the lab and find that its body temperature and metabolic rate change with the ambient temperature. You conclude that it is an ectotherm. c. You note that its environment has a high and stable temperature. Because its body temperature matches the environmental temperature, you conclude that it is an ectotherm. d. You measure the metabolic rate of the reptile, and because it is higher than that of a related species that lives in temperate forests, you conclude that this reptile is an endotherm and its relative is an ectotherm.

Verified step by step guidance

1. Step 1: Understand the difference between endotherms and ectotherms. Endotherms are animals that primarily generate their body heat from internal metabolic processes, and they maintain a stable body temperature regardless of the environment. Ectotherms, on the other hand, rely on external heat sources and their body temperature changes with the ambient temperature.
2. Step 2: Evaluate option a. Just because an animal has a high and stable body temperature does not necessarily mean it is an endotherm. Ectotherms can also have high body temperatures if they live in a warm environment. Therefore, this option is not sufficient to determine if the reptile is an endotherm or ectotherm.
3. Step 3: Evaluate option b. If the reptile's body temperature and metabolic rate change with the ambient temperature, it is likely an ectotherm. This is because ectotherms rely on external heat sources and their body temperature changes with the environment. Therefore, this option suggests that the reptile is an ectotherm.
4. Step 4: Evaluate option c. If the reptile's body temperature matches the environmental temperature, it could be an ectotherm. However, this alone is not sufficient to determine if the reptile is an ectotherm, as endotherms can also maintain a body temperature that matches a warm environment. Therefore, this option is not sufficient to determine if the reptile is an endotherm or ectotherm.
5. Step 5: Evaluate option d. If the reptile's metabolic rate is higher than that of a related species that lives in temperate forests, it could be an endotherm. This is because endotherms generate their body heat from internal metabolic processes. However, this alone is not sufficient to determine if the reptile is an endotherm, as ectotherms can also have high metabolic rates. Therefore, this option is not sufficient to determine if the reptile is an endotherm or ectotherm.

Key Concepts

Endothermy vs. Ectothermy

Endotherms are organisms that can regulate their body temperature internally, maintaining a stable temperature regardless of external conditions, often through metabolic processes. Ectotherms, on the other hand, rely on environmental heat sources to regulate their body temperature, leading to fluctuations that align with ambient temperatures. Understanding these definitions is crucial for determining the thermoregulatory strategies of the reptile in question.

Metabolic Rate

Metabolic rate refers to the rate at which an organism converts food into energy, which is essential for maintaining bodily functions. In endotherms, metabolic rates are generally higher to support thermoregulation, while ectotherms exhibit variable metabolic rates that depend on external temperatures. Measuring metabolic rates can provide insights into whether an organism is endothermic or ectothermic.

Thermal Environment

The thermal environment encompasses the temperature conditions in which an organism lives, influencing its physiological processes. For ectotherms, the ambient temperature directly affects their body temperature and metabolic activity. In contrast, endotherms can maintain a stable body temperature despite variations in their environment, making the understanding of thermal environments essential for interpreting the reptile's thermoregulatory behavior.