Final answer:
The green color trait in individuals is expressed by a recessive allele. A test cross with a 1:1 yellow to green ratio indicates a heterozygous parent. Punnett squares can predict genotypes in future generations.
Step-by-step explanation:
The allele that results in the expression of the green color trait in the individuals described would be a recessive allele. According to Mendel's genetic findings, the green color is a recessive trait that manifests only when the dominant allele for the yellow trait is absent. In other words, a plant with green pods must have two recessive alleles (gg) since the presence of a single dominant allele (G) would result in yellow pods. When conducting a test cross and observing a 1:1 ratio of yellow to green offspring, it indicates that the parent plant is heterozygous for the trait, carrying one yellow (dominant) allele and one green (recessive) allele (Gg). Punnett square analysis can predict the genotypes of subsequent generations, showing the pattern of inheritance of these traits.