SCIENCE: STAGES OF DEVELOPMENT.

WHICH STRUCTURE IS UNIQUE TO VERTEBRATES?
1. BACKBONE
2. LIMBS
3. BRAIN
4. SKING

1. backbone

2. go through the same developmental stages at different rates.
3. gill slits
4. They both have spines

The correct answer is 1. Backbone. The backbone, also known as the vertebral column or spinal column, is a defining feature of vertebrates, distinguishing them from other animals.

The structure that is unique to vertebrates is 4. They both have spines. Both vertebrates and invertebrates have spines, while structures like limbs, brains, and gill slits can be found in various species and are not exclusive to vertebrates.