BIO 302, Spring 2001

 

Review 1 - Classification, Structure, Metabolism, Growth

 

Provide thorough, but concise, answers to the following questions.
There is no time limit to this test, but it should not take you more than 90 minutes to complete.
The review is closed book.
All questions are worth 20.
If your handwriting is lousy, please type your answers.
Staple all pages together and do not put your name on any page other than this cover page.
Return completed review to me no later than 9:30 am, Wednesday, February 21, 2001.

Name (please print):

Pledge and signature:

 

Answer 6 of the following questions

  1. Next week in the laboratory section of the course, we each will isolate Escherichia coli. Using techniques we have used in the laboratory, describe how you would isolate a clonal population of E. coli and confirm its identity with a good degree of certainty. Include information on finding the bacterium, techniques used, and media/reagents used.

  2. Currently, biologists classify all living organisms as belonging to one of three Domains: Archaea, Bacteria, or Eukarya. Discuss three pieces of evidence supporting this classification scheme. Is there any reason to question this classification scheme?

  3. Streptococcus pyogenes is a facultative anaerobic organism. Unlike most facultative anaerobes, though, this organism is catalase negative. Explain why this feature of S. pyogenes is unusual. In a recent article in the Journal of Bacteriology, researchers reported that S. pyogenes does possess an enzyme named NOXase that catalyzes the direct four electron reduction of O2 to H2O. Explain the significance of this finding. Suppose you constructed a NOXase deficient mutant of S. pyogenes. Describe the expected growth characteristics of this mutant.

  4. The hyperthermophilic prokaryotes appear to possess several properties that enable them to flourish at exceedingly high temperatures. Discuss some of these properties.

  5. The cyanobacteria are photoautotrophs that possess a photosynthetic mechanism very similar to the photosynthetic mechanism found in plants. Other prokaryotes, however, possess autotrophic processes that differ significantly from those found in plants. Provide a detailed description of one such non-plantlike autotrophic mechanism.

  6. Explain Figure 1. Include a brief description of how "activity" may have been measured. What is the purpose of these experiments? What would you do next?

  7. Figures 2 and 3 show the metabolism of glucose, galactose, and lactose by Lactococcus lactis. Explain these figures. As part of your answer, discuss the advantages and disadvantages of producing lactate, formate, acetate, and/or ethanol as final products as opposed to another possible final product.