An animal with a backbone is referred to as what?

An animal with a backbone is referred to as a vertebrate. Vertebrates belong to the subphylum Vertebrata, which includes animals such as mammals, birds, reptiles, amphibians, and fish. The defining characteristic of vertebrates is the presence of a vertebral column, or spine, which provides structural support and protects the spinal cord.

This classification is essential in understanding animal biology and ecology, as vertebrates generally exhibit more complex structures and behaviors than invertebrates, which lack a backbone. Vertebrates also possess distinct organ systems and a greater degree of mobility.

In contrast, invertebrates, which are represented in the first option, encompass all animals without a backbone, including insects, arachnids, mollusks, and others. The terms exoskeleton and feline refer to different concepts; exoskeleton pertains to a hard external structure found in some invertebrates like insects and crustaceans, while feline specifically refers to members of the family Felidae, which includes cats, both domestic and wild. Understanding these classifications is vital for anyone studying animal biology or involved in environmental sciences.