NEET BIOLOGY

Detailed explanation-1: -Birds have a streamlined body and hollow bones that make their bodies lightweight. The light chest muscles help in the movement of the wings.

Detailed explanation-2: -Instead of heavy jaws and teeth, they have lightweight beaks. And instead of fur, they have feathers. These are light, streamlined and cleverly adjustable for flight control. Their bones are also hollow (pneumatised) making them lighter for flight.

Detailed explanation-3: -In order to attain the lift necessary for flight, birds have evolved a number of modifications to their skeletal system, including pneumatic, or hollow bones, and reduction of the number of bones by loss or fusion. Hollow, air-filled bones lighten the weight of the skeleton.

Detailed explanation-4: -The wings are the bony parts of the forelimbs that help to fly in the air. They have strong shoulder bones and large breastbones because these bones control the muscles during the flight.

Detailed explanation-5: -Three physical characteristics in particular indicate unique adaptations to their environment: beaks (bills), feet, and plumage (feathers). Natural selection is the mode of evolution that makes living things well-suited (adapted) to their environments.