What is the difference between the bone of a rabbit and that of frogs?
A. In the bone of rabbit, haversian canal is found
B. Yellow marrow is found
C. Osteocytes are of different types
D. Bone of frog is spongy

Hint: Bone is a specialised connective tissue and are hard and compact structures. Arrangements of bones give a structural framework to the body of an organism. Also, the difference in the structure of bones can be observed in certain organisms according to their functions.

Complete answer: The durability and hardness of bones are provided by the calcium salts and collagen tissue fibres present in bones. They have solid ground substance while cartilages have ground substance or matrix that is pliable in nature. The main functions of bones include providing a shape and structure to the body and also to provide protection for soft internal organs from damage. Mammalian bones differ from other bones by having a specialized canal system. They are called haversian canals. These canals contain blood vessels and nerve fibres. These canals are also interconnected with each other by canals and Volkmann’s canals. Haversian canals are encircled with concentric layers of compounds like calcium carbonate and calcium pectate. These layers are called lamellae. There are spaces between these layers that contain several radiating cells called canaliculi and it harbors cells known as osteocytes.
Hence the correct option is A.

Note: There are certain organisms that possess specialised bones. Birds are the organisms that possess bones that contain air cavities inside. This feature helps them to float in the air and also for an internal flow of air through the body.