1. Dismiss Notice
  2. Download free Tapatalk for iPhone or Tapatalk for Android for your phone and follow the SDN forums with push notifications.
    Dismiss Notice
  3. Hey Texans—join us for a DFW meetup! Click here to learn more.
    Dismiss Notice
Dismiss Notice

Interview Feedback: Visit Interview Feedback to view and submit interview information.

Interviewing Masterclass: Free masterclass on interviewing from SDN and Medical College of Georgia

Punnett Square Problem ?

Discussion in 'Pre-Medical - MD' started by FreeMeDoctor, Apr 7, 2007.

  1. FreeMeDoctor

    FreeMeDoctor Membership Revoked

    Feb 18, 2007
    Likes Received:
    If you start out with two pure breeing parents and cross them to get an F1 generation then self-cross the F1 generation with itself ( self-cross ) then cross the F2 with themselves ( self the F2 gen ) you will 3:1 ratio of the dominant phenotype in the F3 generation.

    Can anyone show me how to do the punnett square for the selfing of the F2 generation ? The thing I dont understand is how to do a punnett square when there are three different gamete combinations being crossed. This seems impossible to me.

    Thank you for your help.
  2. Note: SDN Members do not see this ad.

  3. StritchMD2011

    StritchMD2011 Member
    10+ Year Member

    Sep 28, 2002
    Likes Received:
    Medical Student
    This isn't a homework help forum.
  4. Sol Rosenberg

    Sol Rosenberg Long Live the New Flesh!
    Physician 10+ Year Member

    Feb 11, 2006
    Likes Received:
    Attending Physician
    You mean gametes with three different traits (trihybrid cross)? The Punnett square has 64 (4 x 16) entries, and is best done as a branch diagram (i.e. don't do all 64 combinations explicitly like in a Punnett square) but is not impossible. I'm sure there's an example in your Genetics book or online somewhere.

Share This Page