In peas, green pods are dominant to yellow pods, and axial flower position is do
ID: 86879 • Letter: I
Question
In peas, green pods are dominant to yellow pods, and axial flower position is dominant to terminal flower position.
a) Define symbols for the alleles of each of the two genes.
b) If a pea plant with terminal flowers that is hetertozygous for green pods is mater with a pea plant that has yellow pods and is heterozygous for axial flower position, what are the expected genotypic and phenotypic propportions of the offspring?
c) If a plant is heterozygous for both traits is mated to a plant has both homozygous for both of the recessive traits, what are the expected genotypic and phenotypic proportions of the offspring.
Explanation / Answer
Answer:
Based on the given information:
a) Define symbols for the alleles of each of the two genes.
b) If a pea plant with terminal flowers that is hetertozygous for green pods is mated with a pea plant that has yellow pods and is heterozygous for axial flower position, what are the expected genotypic and phenotypic propportions of the offspring?
Genotype of pea plant with terminal flowers and heterozygous for green pods is: Ggaa (terminal flowers will only occur, if both alleles are recessive i.e. aa)
Genotype of pea plant with yellow pods and heterozygous for axial flower position is: ggAa (yellow pod color will only occur if both alleles are recessive i.e. gg)
Ggaa x ggAa
Punnett square for this cross is:
Based on this punnett square, there are 4 distinct phenotypes:
c) c) If a plant is heterozygous for both traits is mated to a plant that is homozygous for both of the recessive traits, what are the expected genotypic and phenotypic proportions of the offspring.
Genotype of plant heterozygous for both traits is GgAa
Genotype of plant homozygous for both recessive traits is ggaa
GgAa x ggaa
Punnett square for this cross is:
Based on this punnett square, there are 4 distinct phenotypes:
Ga Ga ga ga gA GgAa GgAa ggAa ggAa ga Ggaa Ggaa ggaa ggaa gA GgAa GaAa ggAa ggAa ga Ggaa Ggaa ggaa ggaa