Question

In a hypothetical population of plants, flower color is determined by a single gene with two alleles. In a population of 500 plants, the following was observed:
Predict the genotype frequencies of the F1 generation following the cross of a pink flowering plant with a white flowering plant. Show the math used for each cross.

Answer 1

Answer:

In the F1 generation

RR = 0%

Rr = 50% (or 0.5)

rr = 50% (or 0.5)

Explanation:

A pink flowering plant has the genotype Rr. It is heterozygous for the allele. The alleles for this gene appears to show incomplete dominance, as the heterozygous phenotype is a blend of the two homozygous genotypes.

A white flowering plant has the genotype rr. It is homozyogous for the white allele

A punnet square of the cross is shown.

The resulting punnet square shows that only Rr and rr genotypes are possible, at a ratio of 50:50 (or 1:1). Therefore, the genotype frequency of Rr is 50%, and rr is 50% in the F1 generation. This can also be written as 0.5. It is not possible to get a red plant, as the genotype RR can not come from this cross

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