Chapter 12 - Patterns of Inheritance - 12.2 Monohybrid Crosses: The Principle of Segregation - Data Analysis - Page 225: 1

1:1 for heterozygous purple:homozygous white for genotype 1:1 purple: white for phenotype

Since the purple F1 has one dominant allele and one recessive allele, and the white flowered plant has only white alleles, the ratio in the purple F1 will control the results, leading half of the time to purple heterozygous plants in the next generation and half of the time to white homozygous plants. Purple heterozygous plants have purple flowers for their phenotype since purple is dominant.