Fact 1: Vertebrate chordates have a backbone.

Fact 2: Chordates Chordates Chordates include fish, amphibians, reptiles, birds, and mammals.

Given the two facts above, answer the question "fish, amphibians, reptiles, birds, and mammals have what?" with the following options: 
- food
 - fur and fat
 - backbone
 - power
 - four limbs
 - retina
 - vision
 - competition


 

   backbone      