Chapter 32 AP Objectives


Chapter 32     Introduction to Animal Evolution
What Is an Animal?
1.List the five characteristics that combine to define animals.
2.Describe the role of Hox genes in animal development.
The Origins of Animal Diversity
3.Describe the evidence that suggests animals may have first evolved about a billion years ago.
4.Explain the significance of the Cambrian explosion. Describe three hypotheses for the cause of the Cambrian explosion.
5.Outline the major grades of the animal kingdom based on symmetry, embryonic germ layers, the presence or absence and type of coelom, and protostome or deuterostome development.
6.Distinguish between radial and bilateral symmetry. Explain how animal symmetry may match the animal’s way of life.
7.Distinguish among the acoelomate, pseudocoelomate, and coelomate grades. Explain the functions of a body cavity.
8.Distinguish between the following pairs of terms:
a. diploblastic and triploblastic
b. spiral and radial cleavage
c. determinate and indeterminate cleavage
d. schizocoelous and enterocoelous development
9.Compare the developmental differences between protostomes and deuterostomes, including:
a. pattern of cleavage
b. fate of the blastopore
c. coelom formation
10.Name five major features of animal phylogeny that are supported by systematic analyses of morphological characters and recent molecular studies.
11.Distinguish between the ecdysozoans and the lophotrochozoans. Describe the characteristic features of each group.



Build a Bug





Most adult insects have the following characteristics:

    1. A body divided into three parts (head, thorax and abdomen)
    2. Three pairs of legs
    3. Usually one pair of antennae and a pair of compound eyes (a few exceptions to these characteristics are found)
    4. Usually two pairs of wings (absent in many insects such as lice, fleas, ants; flies have one pair of wings)

There are approximately 30 orders of insects. Choose one of the insects from these orders.


Click on the link to learn more about the characteristics of that order. There are links to specific insects on each page.  Visit the Field Guide Index to see a listing of all insects featured in the Field Guide.


Students will build biologically correct insects in order to learn insect structure and adaptations.


Any non-food item such as cardboard, egg cartons, clay, wire, felt, Styrofoam, pipe cleaners, nylon stockings, pipe cleaners, paint, glue, string, etc.


  1. Your model must be an INSECT (i.e. no spiders, mites, ticks, centipedes, or millipedes, please). Note: Your insect does not have to live in the United States.
  2. Your model must be between 6-12 inches long, and sturdy.
  3. Be accurate when building your model (appropriate proportions, true color and form, etc.).
  4. The more detail your model has, the better.
  5. A written description must accompany your model and include:
  • The common name of the insect
  • The name of the order to which it belongs
  • A brief description of the insect’s habitat
  • Where the insect is located geographically
  • At least 2 interesting, and unique facts about the insect you have modeled (i.e. “it has 6 legs and 3 body segments” doesn’t count)
  • Your name and address on model description

Examples of Models:



Spiny KatydidMonarch
DragonflyDamselflyLuna Moth
Walking StickGrasshopperYellow jacket
Atlas MothCarpenter antPraying Mantid