Assume that plant height is determined by a pair of alleles at each of two loci (A and a, B and b) that are additive in their ef
fects. Further assume that each allele represented by an uppercase letter contributes 6 feet to height and that each allele represented by a lowercase letter contributes 2 foot to height. If a plant with genotype AaBB is crossed to a plant with genotype aaBb, what heights are expected in the progeny
1 answer:
Answer:
16 feet, 20 feet, and 12 feet
Explanation:
Uppercase allele = 6 feet
Lowercase allele = 2 feet
First, let us look at the outcome of the cross between AaBB and aaBb.
AaBB x aaBb
Progeny:
4 AaBB = 6+2+6+6 = 20 feet
4 aaBB = 2+2+6+6 = 16 feet
4 AaBb = 6+2+6+2 = 16 feet
4 aaBb = 2+2+6+2 = 12 feet
<em>The heights expected in the progeny are 16 feet, 20 feet, and 12 feet.</em>
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Answer:
All crosses and proportions, genotypes and phenotypes are attached.
Explanation:
a. Within living organisms, staining is a characteristic governed by a polygenic inheritance, which means that there is more than one gene involved in the staining process. as you already know, each gene has two alleles, if a trait is controlled by 2 genes, it means that we will have 4 alleles at the crosses.
From the description between dominance and recessivity between the alleles that control the colors of the pepper, shown in the question above, we can see that for the crossing between a red pepper and a green pepper, being able to generate a completely orange offspring, it would be necessary that the genotype of the parent peppers was: Red: RGRG, green: rgrg.
This would generate an orange-colored RrGg offspring, as you can see at the F1 crossing.
b. When individuals of F1 offspring are crossed, the combination of alleles and the determination of genotypes and phenotypes becomes much more complex, because instead of 4 alleles, we will have the combination of 16 alleles among themselves. Once again we will need to rely on the description of dominance and recessivity shown in the question above, so that from the crossing between the alleles of each gene, we can reach a conclusion, as you can see in the F2 crossing.
