Question

Imagine if we have only one single as our back bone , instead of small bones. Would movement have been possible?

Answer 1

No movement would had not been possible without the last part of the backbone-coccyx.

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.