Mendel’S Pea Plants Had Either Purple Or White Flowers. This Means That The Plants

Mendel’s pea plants displaying either purple or white flowers indicates that the flower color trait in these plants is controlled by simple Mendelian inheritance with two alleles: one for purple flowers and one for white flowers. Typically, in Mendelian genetics, this would suggest the presence of dominant and recessive alleles. Here’s a breakdown of what this means:

1. Dominant and Recessive Alleles:
   • The allele for purple flowers (P) is dominant.
   • The allele for white flowers (p) is recessive.
2. Possible Genotypes and Phenotypes:
   • Plants with at least one dominant allele (PP or Pp) will display purple flowers.
   • Only plants with two recessive alleles (pp) will display white flowers.
3. Inheritance Patterns:
   • If a plant with genotype PP (homozygous dominant) is crossed with a plant with genotype pp (homozygous recessive), all offspring (F1 generation) will be Pp and exhibit purple flowers.
   • If two F1 generation plants (both Pp) are crossed, the F2 generation will exhibit a 3:1 phenotypic ratio (three purple-flowered plants for every one white-flowered plant) and a 1:2:1 genotypic ratio (1 PP : 2 Pp : 1 pp).

This pattern was key to Mendel’s discovery of fundamental principles of inheritance, such as the concepts of dominant and recessive traits, and it highlighted the predictable nature of genetic inheritance.