Based on this information, what is this plant's phenotype for the flower color trait?

 - dark yellow flowers
 - light yellow flowers
The rose plant's genotype for the flower color gene is FF. The rose plant's genotype of FF has only F allelles. The F allele is for light yellow flowers. So, the rose plant's phenotype for the flower color trait must be light yellow flowers.
To check this answer, consider whether the rose plant's alleles are dominant or recessive. The allele for light yellow flowers (F) is dominant over the allele for dark yellow flowers (f). This means F is a dominant allele, and f is a recessive allele.
The rose plant's genotype of FF has two dominant alleles. An organism with at least one dominant allele for a gene will have the dominant allele's version of the trait. So, the rose plant's phenotype for the flower color trait must be light yellow flowers.