Final answer:
Four o'clock plants inherit pigment from both male and female parents, with a pattern of inheritance that can show incomplete dominance. In Mendelian experiments, flower color followed a dominant-recessive pattern with a 3:1 ratio in the F2 generation.
Step-by-step explanation:
The gender of the parent from which four o'clock plants inherit their pigment is not specified in the provided reference materials. However, the inheritance of flower color in plants, such as the ones described in the Mendelian experiments, is typically determined by alleles of specific genes contributed by both the male and female parents. Pigment inheritance in four o'clock plants (Mirabilis jalapa) is an example of incomplete dominance, where the heterozygous offspring exhibit a mix of the parental phenotypes; if one parent has red flowers and the other has white, the resulting heterozygous offspring would have pink flowers.
In Mendel's experiments, when crossing a true-breeding purple flowered plant with a true-breeding white flowered plant, all F1 generation plants had purple flowers. This indicates that the purple flower allele is dominant over the white flower allele. In the F2 generation, there was approximately a 3:1 ratio of purple to white flowers, fitting the Mendelian inheritance pattern.