Question

what would happen, if our backbone was made up of one single bone

Answer 1

if we had only one back bone we will stand like a tree without any movement

Answer 2

our backbone is made of a numerous bone which is fixed with elastic cartilages like structure.our backbone helps us to bend,stretch.etc

if we had a backbone made up of one single bone then we wouldnt have been able to bend nor stretch or do any activities because bones arent flexible.