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Explaining the 9:3:3:1 phenotypic ratio genotypically?

  1. Aug 29, 2012 #1
    In a dihybrid cross of let's say pea plants we get the famous 9:3:3:1 phenotypic ratio. Could this phenotypic ratio be explained genotypically?
  2. jcsd
  3. Aug 29, 2012 #2


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    I'm not sure what you mean, how would you like it explained? Do you understand how dominance works?
  4. Aug 29, 2012 #3
    Yes I know how dominance works.

    I reached the 9:3:3:1 by the branch diagram as well as by using the punnett square.

    As far as "how would you like it explained?"

    Well frankly any way possible. Just try to make it easy to understand.

  5. Aug 30, 2012 #4
    If you reached the 9:3:3:1 using a Punnett square, then I don't see the issue. A Punnett square is a probability map of all the genotypic possibilities.
  6. Aug 30, 2012 #5
    Definitely Yes. Check what genotypes the one's with a particular phenotype have. Based on which allele is dominant you get the coressponding phenotype.
  7. Aug 30, 2012 #6
  8. Aug 30, 2012 #7


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    Hopefully this image will help, it has both the genotypes (with the alleles R, r, Y and y) and the phenotypes (Round, wrinkled, Yellow, green)

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