The ranges of body temperatures of two desert animal species are illustrated - HSC - SSCE Biology - Question 8 - 2006 - Paper 1

To determine the best description, we first analyze the body temperature ranges illustrated for both Species I and Species II.

1. Understanding Ectothermy and Endothermy:

   • Ectothermic animals rely on external environmental conditions to regulate their body temperature. Their body temperatures tend to be more variable and correlate with the surrounding temperature.
   • Endothermic animals generate their own body heat through metabolic processes, allowing them to maintain a relatively constant body temperature regardless of external conditions.

2. Analyzing the Temperature Ranges:

   • Since the temperature ranges for Species I and II are clearly defined, we should consider the characteristics of these ranges. Typically, if a species shows a wide range of body temperatures correlating with environmental changes, it suggests ectothermy.
   • In contrast, a narrow and consistent range may suggest endothermy.

3. Conclusion:

   • Based on the given temperature ranges, Species I might demonstrate ectothermic characteristics, while Species II could potentially be endothermic, as indicated by the variability of temperatures.
   • This leads us to conclude that the best description is (B) Species I is ectothermic; Species II is endothermic.