Wildlife biology

Exercise 3: Sponge Defenses

Read "How Do We Know about Sponge Defenses?" in section 9.2 of ebook.

Answer the following questions:

1. Why are sponge spicules not effective defensive structures against fish predators?

2. How do you think sponge spicules prevent encroachment by anemones that may compete for sponge living space?

3. List 2 sponge metabolites (from section 9.2 of your ebook) that have protective characteristics against predators. Then, do a little internet research-what other organisms produce these same metabolites?

4. With regards to growth and distribution, how do chemically defended sponge species differ from undefended sponge species? Why the differences?

Exercise 4: Planarian Regeneration and Stem Cells

Watch the video "Planarian Regeneration and Stem Cells" Link

1. What human organ can regenerate an entire piece if it has been lost through damage or surgery?

2. Which vertebrate can regenerate an entire limb?

3. Planarians are in the phylum _______________, class ______________.

4. Planarians ingest their food using a ______________.

5. Planarians are described as ______________ phototactic; they move away from light.

6. If cut in half in the laboratory, planarians regenerate the missing half. In their natural

environments, do planarians regenerate? If so, how is this beneficial?

7. The stem-like cells in planarians are called ________________.

8. How many genes have been found to be involved with regeneration in planarians?

9. The protein SMEDWI found in planarians is similar to proteins found in ___________ and

______________.

10. What benefits to humans might be made through planarian regeneration research?