Question

an experiment to measure the rate of respiration in crickets and mice at 10°c and 25°c was performed using a respirometer, an apparatus that measures changes in gas volume. respiration was measured in ml of o₂ consumed per gram of organism over several five - minute trials, and the following data were obtained.
according to the data, the mice at 10°c demonstrated greater oxygen consumption per gram of tissue than did the mice at 25°c. this is most likely explained by which of the following statements?
the mice at 10°c had a higher rate of atp production than the mice at 25°c.
the mice at 25°c were more active than the mice at 10°c.
the mice at 25°c weighed less than the mice at 10°c.
the mice at 10°c had a lower metabolic rate than the mice at 25°c.

Explanation:

• Mice are endotherms (warm - blooded). They need to maintain a constant body temperature. At \(10^{\circ}C\), the environment is cooler. To maintain their body temperature, they have to produce more heat.
• Cellular respiration is the process by which cells produce ATP. Heat is a by - product of cellular respiration. A higher rate of oxygen consumption (as seen in mice at \(10^{\circ}C\)) indicates a higher rate of cellular respiration.
• Since ATP is produced during cellular respiration, a higher rate of oxygen consumption (in mice at \(10^{\circ}C\)) implies a higher rate of ATP production compared to mice at \(25^{\circ}C\) (where less heat needs to be generated to maintain body temperature).

• Option 2: If mice at \(25^{\circ}C\) were more active, they would consume more oxygen, which is not the case as per the data (\(0.0518>0.0321\) for mice at \(10^{\circ}C\) and \(25^{\circ}C\) respectively).
• Option 3: The data is given per gram of tissue (\(mL O_2/g/min\)), so weight difference (if any) is already accounted for in the units of the data.
• Option 4: A lower metabolic rate would mean lower oxygen consumption. But mice at \(10^{\circ}C\) have higher oxygen consumption, so this option is incorrect.

Answer:

The mice at \(10^{\circ}C\) had a higher rate of ATP production than the mice at \(25^{\circ}C\).