Question

Which of the following is an advantage that ectotherms have over endotherms of the same size? a. They require much less food. b. They are less vulnerable to predation during cold weather c. They can remain active in cold weather or on cold nights. d. They have higher metabolic rates and grow more quickly.

Short answer

The correct answer is option (a): Ectotherms have an advantage over endotherms of the same size because they require much less food. This is due to their reliance on external heat sources and lower metabolic rates.

Step-by-step solution

Understand the differences between ectotherms and endotherms

Ectotherms are animals that rely on external sources of heat to regulate their body temperature, like reptiles and amphibians. Endotherms, on the other hand, are animals that maintain a stable internal body temperature through metabolic processes, like mammals and birds.

Analyze each option in terms of ectotherms' and endotherms' characteristics

a. Ectotherms require much less food than endotherms because they rely on external sources of heat, which means they have lower metabolic rates and are not constantly burning energy to produce heat like endotherms do. b. Ectotherms are less vulnerable to predation during cold weather because they can't rely on their metabolism to regulate their body temperature, and this could be seen as a disadvantage since their activity levels decrease with a cold environment. c. Ectotherms can't remain active in cold weather or on cold nights simply because they rely on external sources of heat, unlike endotherms that can maintain their body temperature through metabolic processes. d. Ectotherms have lower metabolic rates due to their dependence on external heat sources; this results in slower growth rates compared to endotherms that can generate heat internally, allowing them to grow more quickly.

Determine the correct option

Based on the analysis of the options, we can conclude that option (a) They require much less food, is an advantage that ectotherms have over endotherms of the same size.

Key concepts

Thermal Regulation in Animals

Animals have developed various strategies to cope with the thermal challenges of their environments. These strategies fall into two broad categories based on the source of heat used to regulate body temperature: ectotherms and endotherms.

Ectotherms, such as reptiles, fish, and amphibians, do not produce much metabolic heat and instead rely heavily on environmental heat. Sunbathing to increase body temperature or seeking shade to cool down are typical behaviors of ectotherms. Because they don't need to generate heat internally, ectotherms have lower energy demands and therefore require less food compared to endotherms.

Endotherms, like birds and mammals, maintain a stable internal body temperature, primarily through metabolic heat production. This ability to thermoregulate provides greater resilience to fluctuations in environmental temperature, allowing endotherms to maintain high levels of activity across a range of conditions. However, this comes at the cost of significantly higher food consumption to support the energetic demands of heat production.

Metabolic Rates

Metabolic rates are a core aspect influencing how animals interact with their environment. Metabolic rate refers to the speed at which an organism converts food into the energy required for survival, including maintaining body temperature, growth, and activity.

Ectotherms typically exhibit lower metabolic rates since they don't rely on internal heat generation. This allows them to survive on less food, but it also means their activity can be limited by the external temperature. For instance, colder days may see ectotherms becoming lethargic as their body processes slow down.

In contrast, endotherms maintain higher metabolic rates, fueled by greater food intake. The rigor of their metabolic activities enables them to keep their body temperature consistent, even in colder environments, granting them the ability to remain active and grow at a faster pace.

Adaptations to Cold Environments

Adapting to cold environments is vitally important for survival, and animals have evolved various physical and behavioral strategies to tackle the challenges posed by the cold.

Ectotherms might adopt behaviors such as hibernation or brumation, where they enter a dormant state to conserve energy during the coldest periods. They might also utilize microhabitats - like burrowing into soil or submerging in water - which offer more stable thermal conditions.

Endotherms, on the other hand, have developed insulative adaptations such as fur, feathers, and fat layers to trap heat. Some also exhibit behaviors like shivering to generate additional metabolic heat. Many birds migrate to warmer areas in response to seasonal temperature changes, while mammals may store food or increase their body mass in preparation for winter, ensuring their high metabolic rates can be sustained throughout the cold season.