Answer: Osteocytes
Explanation:
The backbone is a major component of the vertebral skeleton. It consists of living bone cells (osteocytes), protein fibres (collagen) and minerals, mainly calcium phosphate and calcium carbonate.
Thus, osteocytes are the small units of backbone
Answer: The ossicles
Explanation:
The smaller parts of spinal cord bones are called the ossicles. They joined to make up the long spinal cord.