Question

Bird vertebrae are
(a)Acoelous
(b)Heterocoelous
(c)Amphicoelous
(d)Procoelous

Answer 1

Hint: The vertebra of a bird is convex at one end and concave at the other end; this is to provide proper movement of the birds' neck. Thus the vertebrae are having saddle-shaped ends.

Complete answer:
The bird vertebrae are heterocoelous. Since this is the necessity for birds to have high flexibility for the lateral or ventral movement of their neck without stretching the nerve cord, for only this reason the centrum in the vertebrae is saddle-shaped. So, the birds are having heterocoelous vertebrae which are characterized by saddle-shaped ends of the vertebrae.

Additional Information: -The presence of a vertebral column is the characteristic of vertebrate animals. This column runs from the neck to the tail region.
-The vertebral column or backbone consists of a series of interlocked bones.
-Based on the centrum or the anterior middle portion of vertebrae, the entire vertebral column can be divided into four types
-Different class of vertebrates animals have different kinds of vertebral columns.
-In mammals, the vertebrae are acoelous where the vertebrae are flat from both sides.
-Amphicoelous vertebrae are found in fishes. In this type, cavities are present on both sides of the centrum.
-Procoelous vertebrae are found in reptiles. In this type, the vertebrae are concave at the anterior end of the centrum whereas the vertebrae are convex at the posterior end of the centrum.
So, The correct option is ‘B’.

Note:
-Heterocoelous vertebrae are concave on one axis and convex on the other axis.
-The heterogeneous vertebrae have saddle-shaped ends, which means they fit together like one saddle placed upside down on the other one at ninety degrees.
-This type of vertebrae is one of the most flexible of vertebral joints and is found in the free vertebrae of birds, especially in the neck region.