Which of the following is NOT an invertebrate example?

Which of the following is NOT an invertebrate example?

• A. Goldfish
• B. Jellyfish
• C. Insects
• D. Clams

Answer: (A)

The main idea is telling apart animals with backbones from those without. A backbone means the animal is a vertebrate. The goldfish has a spine, so it is a vertebrate and not an invertebrate. Jellyfish lack backbones; they are invertebrates. Insects also do not have backbones—they have an external skeleton and no vertebral column, so they are invertebrates. Clams are mollusks without backbones, so they are invertebrates. Because only the goldfish has a backbone, it is the one that is not an invertebrate.

The main idea is telling apart animals with backbones from those without. A backbone means the animal is a vertebrate. The goldfish has a spine, so it is a vertebrate and not an invertebrate. Jellyfish lack backbones; they are invertebrates. Insects also do not have backbones—they have an external skeleton and no vertebral column, so they are invertebrates. Clams are mollusks without backbones, so they are invertebrates. Because only the goldfish has a backbone, it is the one that is not an invertebrate.