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Biology Qual


Spring 2020 Biology Qual Session

This Guide is intended to be a resource for you during your Biology Qual and includes links to digital resources ranging from dictionaries and encyclopedias to databases and subject specific resources. 

For specific information on dates, preparation, and format, please go to this Biology Department page:

Really Old Sample Questions

  1. Animal Behavior is often cited as an integrative discipline and, indeed, it is classified as such by the National Science Foundation. Niko Tinbergen, who shared the Nobel Prize in 1973 for his work on animal behavior, argued that there are four fundamental questions to be addressed in the study of behavior. In your essay, outline Tinbergen's four questions, make an argument for which one you believe is the most integrative across various sub-disciplines of Biology, and provide examples of two studies from the primary literature that substantiate your view. In discussing these examples, give particular emphasis to the framework and methods used by the researchers.

  2. The ecological niche of a species or population is not a static feature, but rather it is subject to a variety of sources of variation. What factors would cause the ecological niche of a species to vary over time?

  3. Sea-run cut-throat trout stop drinking when they re-enter fresh water to spawn, but start drinking again upon their return to the ocean. Why?

  4. In the fly embryo, transplantation of cytoplasm containing bicoid mRNA or protein to a recipient embryo results in formation of head and thoracic structures at the receiving site. This is the same sort of result obtained when the Spemann organizer is transplanted, that is, a second head forms. What is the essential difference in mechanism of action between the transplanted bicoid and the transplanted organizer?

  5. Pathogenic Gram negative bacteria possess type III secretion systems enabling them to inject effector proteins directly into the cytoplasm of host cells, disrupting cellular functions. The signal for proteins to be secreted by the type III system is not well understood. It has been hypothesized that the signal may lie in the N-terminal amino acid sequence of the protein or alternately in the leader region of the mRNA coding for the protein. Using the primary literature, present the evidence for both hypotheses. Are these hypotheses mutually exclusive, or is it possible that the type III system recognizes both types of signals for secreting effector proteins into the host cell cytoplasm?

  6. The genomes of most eukaryotic organisms appear to contain a vast amount of DNA that is "non-coding."  Discuss two examples of "junk DNA."  Using experimental observations, formulate and *justify* an argument for or against this definition for your example cases. 

  7. Water permeability of plant membranes is largely dependent on aquaporins. Use the primary literature to develop a discussion of aquaporins in plants which encompasses the evidence for their presence and function in plants. Also discuss their fundamental molecular features. Present a detailed experimental design that would allow you to determine if aquaporins are present in a previously uncharacterized plant species.