| 1.Why is Amphioxus a chordate but not a vertebrate? Explain | 1._________________________________________
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| 2. Why is Amphioxus a very suitable specimen to use for studying the phylogeny of chordates? | 2. |
| 3. Does amphioxus appear to be specialized or generalized? Give some examples to explain how this could be of advantage in evolution. | 3. | 4. How is the generalized structure of amphioxus more like that of an eel than of a salmon? | 4. |
| 4. b) Why are the cirri so critical to amphioxus considering it's eating behavior? | 4. b) | 5. How are the muscles of amphioxus similar to that of a fish? (focus carefully and adjust the diaphragm on your microscope) | 5. |
| 6. Why is amphioxus placed "higher" in the phylogenetic chart than tunicates or acorn worms? (Study your notes on tunicates and observe both larval and adult stages of tunicates. | 6. |
| 7. What is evolutionary opportunism and how is it illustrated by the gill slits of amphioxus? | 7. |
| 8. In what ways is amphioxus like the earthworm ? (study your text on earthworm structure) | 8. |
| 9. How could blood be forced through the vessels of amphioxus although it has no heart? | 9. |
| 10. How can amphioxus obtain oxygen while its gill slits are occupied with filter-feeding? | 10. |
| 11. Examine the projections at the anterior end of the midgut. Use the professional diagrams as an aid. One projection is considered to be the forerunner of the liver. How could evolutionary opportunism promote this change? | 11. |
| 12. Summarize your notes and text on stages in embryological development (ontogeny) of amphioxus. What genetic implications can you offer for why amphioxus develops with the same basic pattern as in vertebrates. Ex: coelom and notochord development. | 12. |
| 13. Why is amphioxus considered to be a relative of the ancestor of all vertebrates. include references to tunicate and eel larva. (Remember: eels are vertebrates) | 13. |
| 14. How is the general pattern of the blood circulation in amphioxus similar to that of a fish? Explain the genetic basis for this similarity | 14. |
| 15. How is the early ontogeny of amphioxus similar to both that of Amphibians and Echinoderms? (Look up Frog and Echinoderm ontogeny) | 15. |
| 16. A long groove in the pharynx secretes mucus and also concentrates iodine! Why is it considered to be a possible forerunner of the thyroid gland? What process could have made this possible? | 16. |
