Question

Tracheal rings of which vertebrate are not of hyaline cartilage but of calcified?

• A. Mammals
• B. Reptiles
• C. Birds
• D. Both (B) and (C)

Answer 1

Answer: (C)

Birds

The trachea is a long, cylindrical and flexible tube running backward through the neck. On entering the thoracic cavity, the trachea expands into a syrinx or voice box. Later it divides into two bronchi, one for each lung.
The walls of tracheal and bronchial tubes are supported by a series of closely set cartilaginous rings. The avian trachea is composed of tightly stacked cartilages which are shaped similarly to signet rings.
Cartilages of the syrinx may be derived from the trachea or bronchi.

Therefore, the correct answer is option C.