Which class commonly undergoes metamorphosis?

• A. Insecta
• B. Arachnida
• C. Crustacea
• D. Myriapoda

Answer: (A)

Metamorphosis is a developmental change where an animal transforms into a markedly different form as it grows. In the major arthropod groups, insects are the ones most commonly showing this pattern. Many insects go through complete metamorphosis, moving from egg to larva to a pupal stage, and then to an adult. The larva often looks very different from the adult and occupies a different lifestyle, like a caterpillar becoming a butterfly or a beetle larva becoming an adult beetle. Others undergo incomplete metamorphosis, with egg, nymph, and adult stages where the young resemble small adults and only gradually reach the full adult form through molts.

Other groups in the choices molt as they grow but do not typically exhibit such pronounced, distinct life stages with completely different body plans. That combination of widespread, dramatic transformation is most characteristic of insects, making them the best answer.