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

To determine the appropriate description of the body temperature ranges for Species I and Species II, we first need to identify their thermoregulation strategies based on their temperature ranges.

• Species I has a body temperature range between 10°C and 40°C, which indicates that it can regulate its body temperature largely through external environmental conditions, typical of ectothermic animals (commonly known as cold-blooded).

• Species II, on the other hand, exists in a body temperature range that is more stable and less dependent on ambient temperature, suggesting it is likely endothermic (warm-blooded), capable of internally regulating its temperature regardless of external conditions.

Thus, the best description that accounts for the body temperature ranges is that Species I is ectothermic; Species II is endothermic, leading to the correct answer being (B).