Final answer:
The frog likely weighs more than the mouse because frogs have a lower metabolic rate per gram of tissue. Since they both consume the same amount of oxygen, the frog must have more mass to account for the total oxygen consumption level observed.
Step-by-step explanation:
The question concerns the comparison of oxygen consumption and metabolic rates between different animals, suggesting a focus on biological principles related to respiration and metabolism. Specifically, it's asking which animal would weigh more based on the fact that a frog and a mouse consume the same total amount of oxygen at 25°C while fasting and at rest. Frogs generally have a lower metabolic rate per gram of tissue compared to mice; hence, if both are consuming the same amount of oxygen in total, the frog is likely to be the heavier of the two because it requires less oxygen per unit of body mass to sustain its metabolic functions.
Key biological concepts here involve understanding the relationship between body size, metabolic rate, and oxygen consumption. Smaller animals, like mice, usually have a higher metabolic rate per gram of body mass than larger animals. Therefore, they consume more oxygen per gram of tissue when compared with animals of larger body mass, such as frogs.