Chapter 28, Problem 19STP

Summary Introduction

To write:

The most primitive metamorphosis complete or incomplete metamorphosis.

Introduction:

The change in the habits and body form during the cyclic development of animals is termed as Metamorphosis

Explanation of Solution

Metamorphosis is a process where an animal physically gets developed after the birth. There are to types of metamorphosis:

1. Complete Metamorphosis

• Those insect whose development is through four stages :the egg, larval, pupa and adult stages. All the stages differ quitely in morphology.
• Complete metamorphosis consist of active and voracious feeding larva and also a pupa which remains inactive.
• The insect’s exoskeleton is molted completely.
• It occurs in wasps, ants, and fleas.

2. Incomplete Metamorphosis

• Those insect whose development where the changes occurs gradually while developing from egg to an adult. This consist of three stages: egg, nymph and adult at last.
• Incomplete metamorphosis consists of nymph, which looks alike small adult.
• Some of the regions of the exoskeleton, remains for a lifetime.
• It occurs in termites, cockroaches, and praying mantis

Conclusion

Thus, between the complete and incomplete metamorphosis the most primitive type is the complete metamorphosis.