What term is used for an animal that does not have a backbone?

What term is used for an animal that does not have a backbone?

• A. Bird
• B. Invertebrate
• C. Vertebrate
• D. Mammal

Answer: (B)

Classification by presence or absence of a backbone is what this question centers on. An animal that does not have a backbone is called an invertebrate. Vertebrates, like birds and mammals, do have a backbone, so they belong to a different group. Invertebrates include a huge variety of organisms—insects, mollusks, worms, and more—across many phyla, all united by the lack of a vertebral column. That’s why the correct term for an animal without a backbone is invertebrate. The other terms describe animals with backbones, so they wouldn’t fit this description.

Classification by presence or absence of a backbone is what this question centers on. An animal that does not have a backbone is called an invertebrate. Vertebrates, like birds and mammals, do have a backbone, so they belong to a different group. Invertebrates include a huge variety of organisms—insects, mollusks, worms, and more—across many phyla, all united by the lack of a vertebral column. That’s why the correct term for an animal without a backbone is invertebrate. The other terms describe animals with backbones, so they wouldn’t fit this description.