Which pair contains only invertebrates?

Which pair contains only invertebrates?

• A. Jellyfish and Insects
• B. Whales and Rattlesnakes
• C. Goldfish and Bullfrogs
• D. Clams and Falcons

Answer: (A)

Invertebrates are animals without a backbone. Jellyfish have no bones, and insects also lack a backbone. So both members are invertebrates. The other pairs mix animals with backbones (vertebrates) with those that don’t, or include at least one vertebrate (for example, whales, rattlesnakes, goldfish, bullfrogs, and falcons all have backbones). Clams are invertebrates, but pairing them with a vertebrate like a falcon isn’t “only invertebrates.” So jellyfish and insects form the pair where both are invertebrates.

Invertebrates are animals without a backbone. Jellyfish have no bones, and insects also lack a backbone. So both members are invertebrates. The other pairs mix animals with backbones (vertebrates) with those that don’t, or include at least one vertebrate (for example, whales, rattlesnakes, goldfish, bullfrogs, and falcons all have backbones). Clams are invertebrates, but pairing them with a vertebrate like a falcon isn’t “only invertebrates.” So jellyfish and insects form the pair where both are invertebrates.