1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: E.coli with minimal media problem, HELP!

  1. Jun 30, 2007 #1
    1. The problem statement, all variables and given/known data
    in the picture/attached file

    2. Relevant equations
    no equations necessary

    3. The attempt at a solution
    don't know how to start it off. I know the E.coli strain can't make the 5 compounds and the colonies present indicate which gene it's missing but I don't know how to determine the gene order from the data.

    can someone give me a hint, please?

  2. jcsd
  3. Jun 30, 2007 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Can you post the a link to the picture or explained the data?

    The attached file is not present.
  4. Jul 1, 2007 #3
    sorry about that, here's the file.

    Attached Files:

  5. Jul 1, 2007 #4


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    That's classical way to do genetics.

    The solution is based on recombination and the chance of unique, double, triple, quadruple, etc, cross-over to occur. In that problem you'll have to assume that only double cross-over occurred. Triple and quadruple are very unlikely and single would destroy the chromosome.

    So to start it up, you need to draw a map of all possible gene order (painful task) and look at all the possible location for cross-over and predict the possible recombinant and phenotype.

    For example

    Donor DNA___A______B______C_________D________E_____

    Possible recombination ABCDE, aBCDE, Abcde, etc

    Phenotype: doesn't need any compound, need compound a, need compound bcde, etc

    Since all your plate have three amino acid added, you only have to look at recombination that exclude 3 genes / fix two genes.
    Last edited: Jul 2, 2007
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook