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: What is linkage strength between gene loci?

  1. Apr 24, 2017 #1
    1. The problem statement, all variables and given/known data
    In linkage strength between any two gene loci is 70%,what would be the amount of crossing over between
    these loci?

    (a) 15% (b)30% (c) 70% (d) none of these.

    2. My approach at understanding the concept

    I didn't find much about linkage strength from any authentic source.
    I can think of two things :
    • The strength of a linkage would be greater if the spatial separation between two genes is less and the lesser if the separation is more. This is semantic. But,
    • how can it be represented in percentage? What does this 100 mean in this 70%? The separation between two genes can be more than 100 map units.
    3. Question in details

    What does linkage strength mean? How is it related to amount of crossing over?

    I would appreciate answers citing some authentic sources.
  2. jcsd
  3. Apr 24, 2017 #2


    User Avatar
    Homework Helper
    Gold Member

    I suppose an authentic source would be the 600+ page 'Dictionary of Genetics'. It is not mentioned there. I have never heard the term used In a technical defined way; I suppose it can be used in a loose way io speaking. I do not understand how you can be asked such a question and are not supplied with a text that gives you a definition. I think genetic distances are usually expressed in centimorgans.

    I would just answer 30% and wait to see if your Prof. gives an explanation.
  4. Apr 25, 2017 #3
    I think it is not a standard term too, if so Google would have shown some results. It was in a question paper, not a homework.

    I also thought that way.
    But using the word linkage strength to mean amount (proportion) of offspring with parental combination of genes is a bit strange.
  5. Apr 25, 2017 #4


    User Avatar
    Homework Helper
    Gold Member

    One usually hears of closeness of linkage rather than strength.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted