Question

Sternum in the bird is
(a) Poorly developed
(b) Well developed
(c) Absent
(d)None of the above

Answer 1

Hint: Flying is the most important characteristic feature of birds, for this purpose it has strong flight muscles. These remain attached to the sternum so the sternum has to be strong.

Complete answer:
The sternum in the bird is well developed. The sternum is the breastbone located in the middle of the chest. It protects the internal organs from injury and is keel-shaped where the powerful flight muscles are attached to the body. Since the powerful flight muscles are attached to it and have to support the bird in flight, so it is well developed.

Additional Information:
-The skeleton of birds is very lightweight because it is made up of mostly thin and hollow bones.
-The sternum is the part of the pectoral girdle and is one of the largest bones of a bird’s skeleton.
-The sternum of a bird is keel-shaped that runs axially along the midline of the chest and it extends outward, perpendicular to the plane of the ribs.
-In the sternum, a convex or concave basal plate is present along with the keel which is perpendicular to it, protruding ventrally.
-The powerful wing muscles are attached to the keel which serves as an anchor to them.
-Since the sternum is treated as a single bone it is actually formed by pairs of unilateral and bilateral homologous elements and it represents one of the most complex elements in the avian skeleton.

So, the correct answer is,’ Well developed’.

Note:
-The sternum is the breastbone located in the middle of the chest.
-The powerful flight muscles are attached to the sternum and have to support the bird in flight, so it is well developed.
-The sternum of a bird is keel-shaped that runs axially along the midline of the chest and it extends outward, perpendicular to the plane of the ribs.