PART - 1 - Unit I : CH - 4 Animal Kingdom — BIOLOGY STD 11 Science — Question

Birds have the following modifications for flying:
(1) The forelimbs are modified into wings which help in flying.
(2) The bones of birds are hollow and light.
(3) The body of birds is streamlined.
(4) The sternum is boat shaped which helps in flying.
(5) Tail helps in direction transportation while flying.
(6) Lungs are spongy non-expandable. Air sacs are found in them which help in flying by lightening the body.
(7) Urinary bladder is absent.
(8) Flight muscles of birds are fully developed, which helps in flying.