Summer squash color is determined by the interaction of more than one gene.The presence of CC or Cc allele combinations produces a squash that is white in color,and the C allele is epistatic to the G allele.The presence of GG or Gg produces a squash that is yellow in color,and ccgg produces a squash that is green.After two fully heterozygous squash are crossed give the phenotypes,and frequency of occurrence,of the F2 offspring.