Desert lizard lack the physiological ability that mammals have deal with the high temperature of their habitat, but manage to keep their body temperature fairly constant by :-

Options

A. Physiological means
B. Behavioural means
C. Biochemical means
D. Anatomical means

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks how desert lizards maintain a fairly constant body temperature despite lacking the physiological adaptations that mammals have for temperature regulation.

2. **Identifying Adaptation Types**: Organisms can adapt to their environments through various means: physiological, anatomical, behavioral, or morphological adaptations. In this case, we need to focus on how desert lizards adapt behaviorally.

3. **Behavioral Adaptation of Desert Lizards**: Desert lizards do not have the same physiological mechanisms as mammals to regulate their body temperature. Instead, they utilize behavioral adaptations.

4. **Specific Behavior**: One key behavior that desert lizards exhibit is burrowing. During the hottest parts of the day, they dig into the ground to escape the extreme heat, which helps them keep their body temperature from rising too high.

5. **Thermoregulation through Basking**: When the temperature drops (for example, in the early morning or late afternoon), desert lizards come out of their burrows to bask in the sun. This allows them to absorb heat and raise their body temperature when necessary.

6. **Conclusion**: Therefore, the desert lizard maintains a fairly constant body temperature through behavioral adaptations, specifically by burrowing to avoid heat and basking to absorb warmth when needed.

### Final Answer:
Desert lizards manage to keep their body temperature fairly constant by **behavioral adaptations**, specifically by burrowing to escape heat and basking in the sun to absorb heat.

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