Final answer:
In sweet peas, purple flower color is dominant over white. A heterozygous purple plant (Vv) crossed with a white plant (vv) would have a 50% chance of each phenotype in the offspring. A monohybrid cross of a true-breeding purple with a true-breeding white would yield all purple F1 offspring and a 3:1 purple to white ratio in the F2 generation.
Step-by-step explanation:
The question is asking about the inheritance of flower color in pea plants and relates to the principles of Mendelian genetics. In sweet peas, purple flower color is indeed dominant over white. When a dominant allele is present, it overshadows the recessive allele, which means that the presence of even one allele for purple color (represented as ‘f’ in the question, although typically represented as ‘P’ in scientific literature) will result in a purple flower.
For example, if we conduct a Punnett square analysis for a cross between plants with genotypes Vv (heterozygous purple) and vv (white), we find that the offspring have a 50% chance of being purple (Vv) and a 50% chance of being white (vv). If we were to look at a monohybrid cross involving a true-breeding purple flower (VV) and a true-breeding white flower (vv), all first-generation (F1) offspring would be Vv and display purple flowers.
Further, if these F1 plants self-pollinate to produce the second generation (F2), the typical Mendelian ratio of 3:1 would be observed, with approximately 75% of the plants having purple flowers and 25% white. This is because the genetic combinations in the F2 generation would be VV, Vv, Vv, and vv, with the first three combinations displaying the dominant purple phenotype and only vv resulting in white flowers.