I’ve been terrible about updating everyone about my class the last few weeks — we’re coming up on the end of the semester, so I’ve been going a little bit mad. We’ve been focusing on vertebrate development lately, and right now we’ve got a few dozen fertilized chicken eggs sitting in an incubator and developing embryos. Maybe. It is always a real pain to get these things delivered to remote Morris, Minnesota — I delayed this part of the lab to the very end of the semester, hoping the sun would emerge and warm the hemisphere enough that when UPS took their sweet time getting them to me, they wouldn’t freeze in the back of the truck. As usual, though, next day delivery turned into two day delivery, and we haven’t seen Spring yet. So we’ll soon know whether they survived their harrowing journey through the frigid Northlands, and if they haven’t, I’ll have to throw up my hands and cry.
Or I could torture my students to ease my frustration. Yeah, that’s the ticket. So it’s exam day.
Developmental Biology Exam #3
This is a take-home exam. You are free and even encouraged to discuss these questions with your fellow students, but please write your answers independently — I want to hear your voice in your essays. Also note that you are UMM students, and so I have the highest expectations for the quality of your writing, and I will be grading you on grammar and spelling and clarity of expression as well as the content of your essays and your understanding of the concepts.
Answer two of the following three questions, 500-1000 words each. Do not retype the questions into your essay; if I can’t tell which one you’re answering from the story you’re telling, you’re doing it wrong. Include a word count in the top right corner of each of the two essays, and your name in the top left corner of each page. This assignment is due in class on Monday, and there will be a penalty for late submissions.
Question 1: One of Sarah Palin’s notorious gaffes was her dismissal of “fruit fly research” — she thought it was absurd that the government actually funded science on flies. How would you explain to a congressman that basic research is important? I’m going to put two constraints on your answer: 1) It has to be comprehensible to Michele Bachmann, and 2) don’t take the shortcut of promising that which you may not deliver. That is, no “maybe it will cure cancer!” claims, but focus instead on why we should appreciate deeper knowledge of biology.
Question 2: There is an interesting tension in evo devo: on the one hand, we like to talk about the universality of molecular mechanisms, but on the other hand, we’re also very interested in the differences, both in phenotype and genetics. This is an old debate in evolutionary theory, too, so it’s not unique to development, but how do you reconcile unity and diversity simultaneously?
Question 3: When I told you about axis specification in Drosophila, the story was relatively straightforward: maternal factors switch on a chain of zygotic genes that set up the pattern. When I told you about the same process in vertebrates, though, I didn’t give you the same level of detail—I gave you buckets of transcription factors and said they had various roles. Dig deeper. Pick ONE of these vertebrate dorsalizing factors out of the bucket and tell me more about it: noggin, chordin, frizbee, goosecoid, pintallavis.