metamorphosis?

Answer 1

It is a complete change.... look here at the definition...


http://dictionary.reference.com/search?r=2&q=metamorphosis

Answer 2

Metamorphosis is a biological process by which an animal physically develops after birth or hatching, involving a conspicuous and relatively abrupt change in the animal's form or structure through cell growth and differentiation.

Some insects, amphibians, molluscs, crustaceans, echinoderms and tunicates undergo metamorphosis, which is usually (but not always) accompanied by a change of habitat or behaviour.
Many insects and amphibians undergo metamorphosis with a significant change in habits and habitat. Immature dragonflies are aquatic, though the adults are flying insects, and frogs undergo a metamorphosis from an aquatic tadpole to an amphibious adult form. Change of habits is illustrated by the transformation of the free-swimming young of many aquatic invertebrates into sessile adults (eg sea squirts), and the development of butterflies and moths from caterpillars with chewing mouthparts into flying insects with sucking mouthparts.

By contrast, many crustacean species undergo significant physical metamorphosis without changing habits or habitat significantly.

It was once thought that, in cases where the animal's habitat remains unchanged, metamorphosis followed a series of forms representing evolutionary ancestors of the species in question (see ontogeny recapitulates phylogeny), but this is no longer thought to be true.


Stages
Metamorphosis usually proceeds in distinct stages, usually starting with larva or nymph, optionally passing through pupa, and ending as adult.

The immature stages of a species that metamorphises are usually called larva. But in the complex metamorphosis of many insect species, only the first stage is called a larva and sometimes even that bears a different name; the distinction depends on the nature of the metamorphosis.

The development of insect larva (like that of other arthropods) often also proceeds in stages called instars advanced by ecdysis (moulting).

Some insects hatch from an egg already having the general form of the adult, and the metamorphosis to adult form is usually marked mainly by the development of wings. This type of metamorphosis is called simple, gradual, or incomplete metamorphosis or hemimetabolism, and the young are called nymphs, or naiads when aquatic. It is often found in the order Mantodea, which is commonly known as praying mantis. They do not undergo stages like a caterpillar to a butterfly, but several stages where the nymph looks like a smaller-sized, wingless adult and ends the metamorphosis with fully developed wings.

By contrast, in complete or complex metamorphosis, or holometabolism the larva markedly differ from the adult. Insects with complete metamorphosis pass through a larval stage, then enter an inactive state called pupa (or chrysalis), and finally emerge as adults. A number of beetle species and Strepsiptera undergo hypermetamorphosis (a sequence of successively simpler larval forms) preceding pupation.

Whether the insect spends more time in its adult stage or in its juvenile form depends on the species. Notable examples of the latter are the mayfly, whose non-eating adult stage lives only one day, and the cicada, whose juvenile stage lives underground for as much as 17 years. These species have incomplete metamorphosis. Typically (though not exclusively), species in which the adult form outlives the juvenile form undergo complex metamorphosis.

Many observations have indicated that cell death plays a considerable role during physiological processes of multicellular organisms, particularly during embryogenesis and metamorphosis.

Answer 3

A change. Like a caterpillar changing into a butterfly.