The basking of Agama lizards in the sun is to

1. Analyze the question The question asks why Agama lizards bask (lie still) in the sun, usually on rocks or walls in the morning.

2. Explain the concept Agama lizards are ectotherms (poikilotherms, or "cold-blooded"). They cannot generate their own body heat internally the way mammals and birds do. Their body temperature depends largely on the environment. To become active (to hunt, move, digest food, and escape predators), they must first warm up. They do this by basking, which is a form of behavioural thermoregulation.

3. Step-by-step solution

• A. Change the colour of their body: Agama lizards do change colour, but this is mainly linked to temperature regulation, mood and display. Basking is not done to change colour, so this is not the purpose.
• B. Raise their body temperature to become active: This matches the ectotherm explanation. In the cool morning, the lizard absorbs solar heat, its metabolism speeds up, and it becomes active.
• C. Fight to defend their territories: Territorial behaviour does occur, but it involves displays such as head-bobbing and chasing, not basking.
• D. Attract the female for courtship: Males do display during courtship, but that is a separate behaviour from basking.

4. Answer The correct option is B. raise their body temperature to become active.

5. Exam tip Remember: "Ectotherm = Excess sun needed." Whenever you see reptiles (lizards, snakes, crocodiles) lying in the sun, think thermoregulation. Also remember that when they get too hot, they retreat into the shade or burrows to cool down.