经过漫长的进化，陆生动物身体表面具有了能减少水分散失的结构。下列结构不具有此功能的是 A. 响尾蛇的...

Considering structures that reduce water loss

Alright, the question is asking which structure does NOT reduce water loss. Let's break it down:

• Rattlesnake scales: These are keratinized and help protect against water loss.
• Cicada exoskeleton: This is made of chitin and often has a wax layer, definitely helping to reduce water loss.
• Rabbit hair: While it serves insulation, it also reduces surface evaporation, but not specifically for water retention like the other two.
• Pigeon skin: This doesn't seem to serve any direct water retention purpose.

I think the right answer is rabbit hair.

Analyzing water loss and adaptations

Alright, the question is asking which structure doesn't reduce water loss. Mammalian skin, covered in hair, relies on keratinized epidermis and sebum to prevent water loss, with hair mainly for insulation. Rabbit hair isn’t primarily for water retention. Pigeon skin, on the other hand, is thin and not particularly water-resistant, though it's covered by feathers. So, I think pigeon skin is the least effective at preventing water loss since the skin itself doesn’t have specialized features like mammalian skin or insect cuticles.

Thought for 16 seconds