Help with amphioxus Labroratory - Bio 11 (Lab#1)

1. PURPOSES
   1. To investigate the 3 main criteria of Chordates
   2. To investigate examples of evolutionary opportunism
   3. To investigate how amphioxus relates to more advanced chordates using a phylogenetic chart
   4. To observe a Tunicate Adult and larva, and relate it to Amphioxus
   5. To understand the significance of paedamorphisis
   6. To relate the larval lamphrey to vertebrate evolution


2. HYPOTHESIS: Simply make a prediction of something you expect to see



3. INTRODUCTION: (suggestions)
   • Write up background information to help a reader understand your lab. Include why amphioxus is very suitable for the lab.
   • What is amphioxus and where is it found?
   • How does it live?
   • Terms:
     • What are the criteria of chordates?
     • What is evolutionary opportunism?
     • What is filter feeding?
     • What are gill grooves and slits?
     • What are Tunicates (sea squirts) and what happens to them in metamorphasis?
     • What subphylum does amphioxus belong to?
     • What is Paedomorphosis?
   • Most of the intro is written in the present tense
   • References should be listed at the end of the report


4. METHODS and MATERIALS:
   1. List materials
   2. Use the past tense to explain what was done to view the interior of the amphioxus (remember: we had to scan it), and a general statement of the structure of the tunicate larva. If you also used a cross-sectional diagram from the handouts, mention this too.


5. RESULTS:

   Produce an Observation and Interpretation chart:

   OBSERVATIONS	INTERPRETATIONS
   ex:1. The gill slits are only found in the front section of the amphioxus.	1. Because the front region contains the pharynx which has a current of water going through it.
   2. Think of more significant observations.	There are many possibilities. Be sure a reason is placed opposite in almost every case.



6. DIAGRAMS:
   
   • They constitute part of your results.
   • Use blank paper and pencil.
   • Label carefully! Two diagrams: Tunicate larva and Amphioxus. Use a caption. Use theory pictures from interactive lectures to help with labelling.
   • Draw each diagram LARGE (ex: amphioxus should be drawn 12cm long)


7. DISCUSSION:
   

   Acronym

   Discuss reasons for results. i P - refer to principles. Speculation and significance. T - refer to theory. Implications. Conclusion and evidence.

   1. Did we see how gill slits could change function? for what? Why would this be logical?
   2. How was the principle of evolutionary opportunism brought in the lab?
   3. How was the principle of the phylogeny brought out? (See handout in phylogeny of Chordates)
   4. How is amphioxus like a lamprey adult? Like a lamphrey larva?
   5. Why couldn't amphioxus be the actual ancestor of vertebrates?
   6. What significance could you attach to the pattern of muscles in amphioxus? *Note: If you did a good job on your observations, you can use material on your chart, but elaborate more on it after more research and extra reading (if you wish).
   7. Why were gill grooves so valuable in later evolution?


8. CONCLUSION:
   
   • Make some general comments on what you got out of the lab and a general evidence for each statement.
   • Ex: Position of amphioxus on the Chordate Phylogenetic chart and why is it there?
   • Ex: There was a lot of opportunity for evolution in an amphioxus-like organism; and why?


9. QUESTIONS:

   Click here to view the two question sheets. One is easy, and the other is challenging.