BNFO 300 
Molecular Biology Through Discovery
Questionnaire on Meselson & Stahl
(please press SUBMIT button when finished)
Fall 2018  


My advice on the matters for the day (as listed in the calendar):

DNA
  • DNA Structure: We're considering only Study Questions 3 through 6 and Part D of the notes on DNA structure. The most unfamiliar part may be the section on palindromes. Study questions 15 and 17 might be good tests as to whether you grasp the concept.
     
  • DNA Replication: Many people consider this section review, but you might find some surprises in the notes on DNA replication. Addressing Study Questions 1, 3, and 4 might help you gauge if you know what you're talking about.
     
  • Meselson & Stahl (1958): Many people have learned of this experiment in previous classes. They say "I already know that DNA replicates semiconservatively", but few really understand what that means. Understanding the experiment that led to a concept will generally make a fuzzy concept tangible. Today is your chance. Do what you need to do to understand the experiment or, failing that, to develop questions that will lead you to understanding. The companion to the article (new version dated Sep 27, 2017) and its study questions may help, particularly Study Questions 2, 7, 9, and 14.
     
  • Exam 2: Take a look at the ground rules and what to expect, and please return the form regarding your availability.
     
  • Problem Set 4: Look over Problems 4.2 and 4.6 before class if you like, or wait until you meet with your groups. It might be helpful before class to familiarize yourself with the Polymerase Chain Reaction, perhaps using the links given in Problem 4.6 to a tutorial
     

I. Basic Information

  1. Your name  
II. Old business (no need to repeat anything you've said in a previous questionnaire)
  1. DNA Structure
    Anything further you'd like to discuss regarding the notes DNA Structure?
    OK with the nature of palindromes? If not, describe your current state of understanding.

     
  2. DNA Replication
    Anything further you'd like to discuss regarding the notes DNA Replication?
    OK with the directionality? Primers? If not, describe your current state of understanding.

     
  3. How to read a research article
    Anything further you'd like to discuss regarding the mini-article (describing an experiment concerning DNA replication) and the suggestions how to go about reading it (and any research article)?

     
  4. Exam 2
    Anything you'd like to discuss regarding the rules of the game or the material that's fair game?
III. Meselson and Stahl
  1. How far have you gotten in Meselson and Stahl (1958) and its companion?

     
  2. Consider how comfortable you are with the following topics regarding Meselson & Stahl:
     
    • The topological problem implicit in the replication model presented by Watson and Crick
    • Dispersive replication, and how it addresses the topological problem
    • The critical differences between the three featured models of DNA replication
    • How heavy isotopes can distinguish new from old DNA
    • What properties of cesium chloride are helpful in this procedure
    • Equilibrium density centrifugation
    • How to read Fig. 4 (e.g. what do position and ultraviolet absorption indicate)
    • The relationship between Meselson and Stahl's results and the predictions of the three featured replication models
    • How Delbrück's topological problem was ultimately resolved

    Please relate your thoughts and current state of understanding
IV. Miscellaneous
Any other comments, questions, suggestions, or concerns you may have?

Thanks!

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