Question

The correct order of life stages in an insect with complete metamorphosis would be:
a) Egg to larva to adult
b) Egg to nymph to adult
c) Egg to nymph to larva to adult
d) Egg to larva to pupa to adult
e) Egg to nymph to pupa to adult

Answer 1

First we must know the exact meaning of metamorphosis. Metamorphosis is defined as a biological process by which an animal physically develops after birth or by hatching which involves a conspicuous and relatively abrupt change in the animal's body structure through the process of cell growth and differentiation.

Complete answer:
Complete metamorphosis consists of four distinct stages namely egg stage followed by larva stage then pupa stage and finally adult stage, while the incomplete or gradual or simple metamorphosis lacks pupa and has three life cycle stages namely egg, nymph, and adult.
Larva is a worm-like structure which eats constantly and grows rapidly into the pupa which has a hard covering. The pupa is then finally transformed into an adult.
In stage 1 which is the Egg - The male and female insects prefer a warm and humid environment for mating which then produces tiny pearl-like eggs which are laid on the surface of the host.
In stage 2 which is the Larvae stage - The larvae emerges out of the egg without the eyes and legs and take shelter on mammals or the nearest carpet fibres it can find. At the end of this stage, the larvae spin silk cocoons and enter the pupa stage. Larvae attach dirt and other debris to camouflage and protect them till they transform into the pupa stage.
In stage 3 - The Pupa stage – In the pupa stage, the insect develops all organs in humid conditions. If the environment is humid and favourable, then the adult will emerge in a week. If the conditions are not favourable, then pupa may take a year to become an adult flea.
In stage 4 which is the Adult stage - Adult feeds on the blood of the host and leaves blood debris which appears as black particles on the exterior of the host. Then the adult insect hunts for a host to reside, lay eggs and feed blood.

Therefore, the correct answer is option D which says Egg to larva to pupa to adult.

Note:
Animals can be divided into species that undergo complete metamorphosis known as holometaboly, incomplete metamorphosis called hemimetaboly or no metamorphosis known as ametaboly. The effect of metamorphosis can modify the entire body of an organism. These variations include the maturation of enzymes, blood cells, the remodelling of the nervous systems, digestive systems and so on.