In the following dihybrid cross in pea plants, the F allele codes for full pods, f codes for constricted pods, the P allele codes for purple flowers, and the p allele codes for white flowers. What is the phenotype of the highlighted box, and what is the predicted frequency of this phenotype?

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According to Mendel's law of independent assortment, alleles of two different genes get sorted into gametes (sex cells) independently of one another. Therefore, the allele one gamete receives for a gene does not influence the allele received for another gene.
In this example, we see a cross between two dihybrids. A dihybrid is an organism that is heterozygous for two genes. This means that the organism has two different alleles for each gene (e.g. AaBb). A cross between two dihybrids is known as a dihybrid cross.
When Mendel did a dihybrid cross with his pea plants, he found that there were four different categories of pea seeds in the offspring: yellow and round, yellow and wrinkled, green and round, and green and wrinkled. These categories, which were defined by observable traits (phenotypes) appeared in a ratio of approximately 9:3:3:1.
In the example in order to have full pods, the dominant F allele must be present in the genotype (could be either FF or Ff). To have purple flowers, which is also a dominant trait, the dominant P allele must be present in the genotype (either PP or Pp). Constricted pods would be two recessive f alleles (ff) and white flowers will also have two recessive p alleles (pp). In our case we have Ffpp. This means that the pods will be full because of the dominant F allele and the color of the flowers will be white because of the recessive p alleles.
So, according to Mendel's predicted ratio, there would be 9 plants with both dominant traits expressed (full pods and purple flowers), 3 plants with one of the recessive trait expressed (full pods and white flowers), 3 plants with the other recessive trait expressed (constricted pods and purple flowers), and 1 plant with both recessive traits expressed (constricted pods and white flowers).

In the Following Dihybrid Cross in Pea Plants, the F