Which order is best known for a silver color and a carrot-shaped body, with chewing mouthparts?

• A. Thysanura
• B. Ephemeroptera
• C. Collembola
• D. Diplura

Answer: (A)

This question tests recognizing the distinctive look of silverfish: a silvery, carrot-shaped, wingless insect with chewing mouthparts. The features described—metallic scales giving a silver sheen, a tapering abdomen like a carrot, and mouthparts adapted for chewing—point to the primitive order that includes silverfish people encounter in homes. These insects are wingless and show ametabolous development, with three long tail filaments at the end of the abdomen, all characteristic of this group. The other orders differ in key ways: mayflies have delicate bodies and wings as adults with often reduced mouthparts; springtails and diplurans lack the classic silvery scales and carrot-shaped form, and their mouthparts/morphology don’t match the combination described.