The backbone, or vertebral column, is a unique feature of vertebrates because it provides support and protection to the spinal cord. It is a segmented structure made up of individual vertebrae that are connected by ligaments and discs. The backbone allows vertebrates to have an upright posture and facilitates movement and coordination of the body. In contrast, invertebrates typically do not have a backbone and instead have other structures that provide support and protection, such as exoskeletons or hydrostatic skeletons.
