Monohybrid Cross and Punnett Square

1.      In garden pea, green pod is dominant over yellow pod. If heterozygous green pod undergone self-pollination, find the phenotypic ratio (P.R.) and genotypic ratio (G.R.) and the percentage of their offspring.

                        *Garden Pea :   green pod – Dominant = GG         

                                               yellow pod – Recessive = gg

                                                                       Hybrid = Gg

                        *heterozygous green pod = Gg

                        *(self-pollination) heterozygous green pod = Gg

                          Monohybrid Cross                              Punnett Square

*Phenotypic Ratio (P.R.):

                                    3 green pod : 1 yellow pod    or    3:1

*Genotypic Ratio (G.R.):

                                    1 homozygous green pod :

                                    2 heterozygous green pod : 

                                    1 homozygous yellow pod

*Percentage:

                                    75% green pod and 25% yellow pod