Chapter 32 Introduction to Animal Evolution
Objectives
| 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 |
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| 9. |
Compare the developmental differences between protostomes and
deuterostomes, including: a. pattern of cleavage b. fate of the blastopore c. coelom formation |
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| 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. | ||
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