In the question, it is given that the purple flowers are dominant to the white flowers. The dominant allele for the flower is P, and the recessive allele for the flower is p.
So, the possible genotypes of the purple flower is - PP or Pp.
And, the possible genotype of the white flower is - pp.
The cross1 shows the cross between PP and pp.
The phenotype of all the offspring in the cross 1 is Purple, and the genotype is pp. Hence, the possibility of getting purple flowers in the progeny is 100%.
Homozygous dominant genotype is the condition, in which the plant's alleles are same and both are dominant.
The cross 2 shows the cross between Pp and pp:
The homozygous dominant genotype (PP) is 1 and the total number of progeny is 4. So, the probability of occurence of PP is 1/4 or 25%.
Hence, the first blank can be filled with 100% and the second blank can be filled with 25%.
