Question

8 list at least three avian developments that make flight possible and efficient. 9 what are the two primary functions of feathers?

Explanation:

For question 8, avian features like lightweight bones, streamlined body shape, and powerful flight - muscles contribute to flight. Lightweight bones reduce body weight, a streamlined body minimizes air resistance, and powerful flight - muscles generate the necessary force for flight. For question 9, feathers primarily serve for flight and thermoregulation. In flight, they provide lift and control, and for thermoregulation, they help insulate the bird's body.

Answer:

1. Lightweight bones, streamlined body shape, powerful flight - muscles
2. Flight, thermoregulation