Question

the back bone or intertwining strands are made up of bones and muscle. the rungs are

Answer 1

the rungs between to bones are small balls

Answer 2

$\huge\purple{Ello \: ♡}$

The structural composition of back bone allows us to bend, crouch, stand and lie down on the ground. The vertebral units promote this movement. If back bone is made up of one long bone then we would never be able to sit, crouch or lie. One single bone means no flexibility in the structure of a bone.