Which metamorphosis type includes four life stages: egg, larva, pupa, and adult?

• A. Egg, larva, pupa, and adult (Complete metamorphosis)
• B. Egg, nymph, adult
• C. Egg, young, adult
• D. Egg, larva, adult

Answer: (A)

Four life stages—egg, larva, pupa, and adult—signal complete metamorphosis. In this pattern, the larval form is usually worm-like and specialized for feeding and growing, while the pupal stage is a transformative, non-feeding phase during which the organism reorganizes into an adult with a very different shape and lifestyle. Because of these distinct stages, many insects such as butterflies and moths, bees and wasps, beetles, and true flies exhibit this four-step development, which helps explain why the adult looks so different from the larva.

The other sequences don’t include a pupal stage or don’t show a dramatic difference between juvenile and adult forms. Egg-nymph-adult describes incomplete metamorphosis, where the nymph resembles the adult and there is no pupal transformation. Egg, young, adult isn’t a standard developmental pattern for insects. Egg-larva-adult omits the pupal stage, so it represents a different type of development and doesn’t capture the full transformative process seen in complete metamorphosis.