Genotype and phenotype probabilities by ternary code based line-dot method and polygonal illustrations

The heart of learning genetics is in realizing that how the likelihood of inheriting a particular trait can be predicted. this fundamental approach is the basis for plant and animal breeding to get desired varieties as well as performing genetic analysis including prediction of patterns of inheritance in family lines and to calculate the recurrence risk for relatives etc. punnett square is used to describe the possible combinations of paternal and maternal alleles for a particular cross. described here is a line-dot method using ternary genotype codes to determine genotype probabilities in a very quick and simple way. also ternary genotype codes along with gender symbols and affection status are used to modify the punnett squares. on applying these modified punnett squares along polygonal shapes covers all possible parental combinations and their genotypic and phenotypic outcomes in offspring. in this way,simple illustrations incorporate a considerable amount of information that provides the opportunity to determine genotype and phenotype probabilities for monogenic mendelian traits without the need to draw punnett square for every parental genotype combination. these illustrations provide information for both forward (phenotype to genotype) as well as reverse genetics (genotype to phenotype) approaches. copyright 2017 zoological society of pakistan.