Which of the following animals undergoes metamorphosis and which do not? Cow, Butterfly, Silk moth, Humans, Frog, Housefly, Sparrow, Hen, Mosquito, Monkey

Animals that undergo metamorphosis from the given list are: Butterfly, Silk moth, Frog, Housefly, and Mosquito. Metamorphosis is a biological process where an animal's body structure changes dramatically during development from juvenile to adult form. Insects like butterflies, silk moths, houseflies, and mosquitoes undergo complete metamorphosis, progressing through distinct life stages—egg, larva (caterpillar or maggot), pupa (chrysalis or cocoon), and adult—with each stage looking and functioning completely differently. Frogs undergo incomplete metamorphosis, transitioning from aquatic, gill-breathing tadpoles to terrestrial or semi-aquatic, lung-breathing adults, with gradual changes including tail resorption and limb development.

Animals that do not undergo metamorphosis are: Cow, Humans, Sparrow, Hen, and Monkey. These animals exhibit direct development, where the newborn resembles a miniature version of the adult and grows progressively larger while maintaining the same basic body plan. Mammals (cow, humans, monkey) give birth to live young that possess the same organ systems and body structure as adults, simply requiring growth and maturation. Birds (sparrow, hen) hatch from eggs as chicks that already display characteristic avian features—feathers, beaks, wings—and develop into adults through gradual growth rather than radical body restructuring. This direct development strategy typically accompanies parental care, where adults protect and nurture vulnerable young, whereas metamorphosis often allows offspring to exploit different ecological niches (caterpillars eat leaves while butterflies drink nectar), reducing competition between life stages and parents.