Gregor Johann Mendel was the father of genetics who developed the three principles of inheritance that describes the transmission of genetic traits by experimenting with pea plant breeding (1). By cross-fertilizing tall and dwarf plants, Mendel discovered genes that were expressed factor as dominant and the latent factor as recessive (2). These dominant and recessive forms are called alleles which are alternate forms of a gene. To study the inheritance of traits, Mendel did a monohybrid cross. A monohybrid cross is a cross between parents “differing in only one trait or in which only one trait is being considered” (book). A monohybrid is an offspring, F1 generation, of the “two homozygous parents that differ from one another by the alleles present at only one gene locus” (2). Mendel also performed experiments with plants that differed in two traits called dihybrid cross. A dihybrid cross is between homozygous parents differing in two respects. A dihybrid is an individual that is heterozygous for two pairs of alleles (2). Three…show more content… Chi-squared tests are used in genetics to infer whether the data obtained fits any of the Mendelian ratios and whether two genes are linked or unlinked by looking at the frequency distribution of potential phenotypes (4). The formula for chi-squared statistics to test for possible discrepancies between observed and expected numbers: x^2=∑〖(Observed-Expected)〗^2/Expected (2). The critical value in chi-squared test is the point where the discrepancies between observed and expected numbers are not likely to be due to chance and to make the decision for the hypothesis about the genetic data. The critical value is determined by the degrees of freedom which is the number of phenotypes minus one. The genetic data has to be 0.51 or less than the critical value for the hypothesis to be true