Question

A true-breeding plant with inflated pods and yellow pods is crossed with a plant that has constricted and yellow pods. Draw a

Punnett square to predict the outcome of this cross. List the possible genotypes and their phenotypes. (Note: Inflated is
dominant to constricted and green is dominant to yellow).

Answer 1

Answer: Sysy × Sysy i.e. all are genotypically heterozygous, inflated, and yellow

Step-by-step explanation:

Punnett squares are a diagrammatic means of determining traits of hybrid offspring produced via crosses in genetic breeding. The parental genotypes and phenotypes are usually known, and these typically follow standard Mendelian ratios and inheritance.

Mendelian genetics focus on trait inheritance, or heritability. These traits are packaged out into its own gamete, inherited by themselves and often show dominance, where one's effect may mask those of another trait.

These are called the Law of Segregation, Independent assortment and Dominance respectively.

For this cross...

Parent generation or P generation:

gametes: Y → pod color green dominant (Y), yellow recessive (y)

S→ pod size; inflated dominant (S), constricted recessive (c)

Assumptions...

• True breeding plants are homozygous, with identical sets of alleles
• The other parent is heterozygous, as it was not said to breed true

P generation: SySy × sysy

yellow, inflated × yellow, constricted

F1 generation: Sysy × Sysy ...(from punnet square)

phenotype: yellow, inflated × yellow, inflated

∴ all are genotypically heterozygous, inflated, and yellow