Biology 2 - Problem sets
Problem Set 1: Phylogeny, Nutrition and Gaseous exchange
Due in class on Friday, April 19th
Please type and spell-check your responses to these questions. Guidelines for length are included with each question. Remember to be thorough but concise and focus on form and function. The "Hmmm" question is a biological puzzle for extra credit.
1. Do you believe that the chloroplasts of photosynthetic protists arose from three or more endosymbiotic events or from a single event which was followed by adaptive radiation? Drawing on information about both bacteria and protists, outline the evidence which supports your claim. In your model of photosynthetic protist evolution, are the different types of chloroplasts homologues or analogs? (1/2 to 1 page)
2. Compare and contrast feeding structures and strategies amongst Zygomycota, Cnidaria, Platyhelminthes, Nematoda, and Annelida. What advantages are gained in developing a more complex system of digestion? What are the costs of a more advanced system? (1/2 to 1 page)
3. Which of the phyla in question #2 are characterized by cephalization? Are they radially or bilaterally symmetrical? What types of foraging strategies are made possible by cephalization? (1 paragraph)
4. Compare and contrast digestion strategies in humans and ruminants. (1-2 paragraphs)
5. Explain the phenomenon of lactose-intolerance in humans, why it occurs, and what treatments are available to mitigate the problem. (1-2 paragraphs)
6. Why does a fern require water for fertilization? Why doesn't an oak tree require water for fertilization? Use the following terms in your answer: gametophyte, sporophyte, alternation of generations, spore, gamete. (1-2 paragraphs)
7. Using text and a diagram, explain counter-current gas exchange in the gills of fish. How does it improve the efficiency of gas exchange? (labeled diagram and 1 paragraph)
Hmmm Our atmosphere is approximately 20% oxygen, but well oxygenated water is only about 0.001% oxygen. So why do fish die when they are out of water? (1 paragraph)
Problem Set 2: Nutrition, Gaseous Exchange and Circulatory systems
Due in class on Friday, May 3rd.
Please type and spell-check your responses to these questions. Guidelines for length are included with each question. Remember to be thorough but concise and focus on form and function. Answer as succinctly as possible. Some of the below questions will require you to research beyond the textbook. Each answer should be between 1/2 page and 3/4 page in length.
1. All digestion across all kingdoms occurs externally. Discuss.
2. Discuss in detail, with the aid of the diagram, the hormonal control of digestion in the stomach. Include in your answer the concepts of positive and negative feedback loops.
3. Describe in detail how the pancreas regulates blood sugar levels with insulin and glucagon. What, physiologically, is diabetes and how is it typically treated?
4. Explain, with the aid of a diagram, the concept of mass flow in plants.
5. Compare and contrast external versus internal respiratory surfaces. What are the advantages and disadvantages of each?
6. Marine mammals have a secondary oxygen carrying compound, myoglobin. Explain why, and discuss its advantages.
(this will definitely require you to do some extra research beyond the textbook):
Choose a heart condition that has a specific, diagnostic EKG trace. Explain the link between the two.
Take-Home Problem Set 3 (due 5/17/02)
to be announced
Take-Home Problem Set 2 (due 6/07/02)
to be announced