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hivesaeed4
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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?
Explaining the 9:3:3:1 phenotypic ratio genotypically?
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In summary, a dihybrid cross of pea plants can result in a 9:3:3:1 phenotypic ratio, which can be explained genotypically by looking at the genotypes of the plants with a particular phenotype and understanding how dominance works. This can be illustrated using a Punnett square or a branch diagram, with the corresponding alleles and phenotypes.
- #2
Ryan_m_b
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I'm not sure what you mean, how would you like it explained? Do you understand how dominance works?
- #3
hivesaeed4
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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.
Thanks.
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.
Thanks.
- #4
aroc91
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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.
- #5
mishrashubham
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hivesaeed4 said:
Definitely Yes. Check what genotypes the one's with a particular phenotype have. Based on which allele is dominant you get the coressponding phenotype.
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hivesaeed4
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Thanks.
- #7
Ryan_m_b
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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)
FAQ: Explaining the 9:3:3:1 phenotypic ratio genotypically?
What is the 9:3:3:1 phenotypic ratio?
The 9:3:3:1 phenotypic ratio is a ratio commonly observed in offspring resulting from a dihybrid cross, where two traits with complete dominance are being studied. It means that for every 16 offspring, 9 will have both dominant traits, 3 will have one dominant and one recessive trait, 3 will have the other dominant and recessive trait, and 1 will have both recessive traits.
How is this ratio determined genotypically?
The 9:3:3:1 phenotypic ratio can be determined genotypically by using a Punnett square. The dominant traits are represented by capital letters, and the recessive traits by lowercase letters. For example, if we are studying the traits of flower color (purple and white) and plant height (tall and short), the genotypes for the dominant traits would be PP and TT, and the genotypes for the recessive traits would be pp and tt. By filling in the Punnett square with these genotypes, we can see that out of the 16 possible combinations, 9 will result in the dominant traits, 3 in one dominant and one recessive trait, 3 in the other dominant and recessive trait, and 1 in both recessive traits.
Why is the 9:3:3:1 ratio important in genetics?
The 9:3:3:1 ratio is important in genetics because it demonstrates the principles of Mendelian inheritance and helps us understand how traits are passed on from parents to offspring. This ratio also allows us to make predictions about the traits that offspring are likely to have based on the genotypes of their parents.
Can the 9:3:3:1 ratio be altered?
The 9:3:3:1 ratio is a theoretical ratio and may not always be observed in real-life situations due to various factors such as incomplete dominance, multiple alleles, or epistasis. In these cases, the ratio may be altered, but the underlying genetic principles still apply.
What other types of ratios can be observed in genetics?
In addition to the 9:3:3:1 ratio, other common ratios observed in genetics include the 3:1 ratio for a monohybrid cross, the 1:2:1 ratio for a dihybrid cross involving incomplete dominance, and the 9:6:1 ratio for a dihybrid cross involving codominance. However, there are many other variations of these ratios that can be observed depending on the traits being studied and the genetic factors at play.