[Campbell Biology P.940] Based on Figure 40.20a and the "INTERPRET THE DATA" section, evalua... | Practice Question

Based on Figure 40.20a and the "INTERPRET THE DATA" section, evaluate the two observers' statements regarding the basal metabolic rate BMR of 100 ground squirrels compared to 1 dog.

  • A: Observer 1 is correct; 100 ground squirrels have a combined BMR similar to one dog.
  • B: Observer 2 is correct because the BMR per kilogram of body mass for ground squirrels is much higher than for a dog, meaning 100 ground squirrels would use far more energy.
  • C: Observer 2 is correct because the BMR of one dog is approximately 20 L O2/hr, while 100 ground squirrels would only have a combined BMR of about 5 L O2/hr.
  • D: Observer 1 is correct because BMR scales inversely with body mass, so a large number of small animals would equate to a large animal's metabolic rate.

Explanation

According to Figure 40.20a, a dog with a body mass of approximately 10 kg has a BMR of about 20 L O2/hr. A ground squirrel with a body mass of approximately 0.1 kg has a BMR of about 0.05 L O2/hr. Therefore, 100 ground squirrels would have a combined BMR of 100 0.05 L O2/hr = 5 L O2/hr. This is significantly less than the BMR of one dog, so Observer 2 is correct.