Mendel's First Law (Segregation): During gamete formation, the two alleles for a heritable character segregate randomly so that each gamete carries only one allele.
Mendel's Second Law (Independent Assortment): Alleles of two or more different genes sort independently into gametes (demonstrated in $4\times 4$ Dihybrid crosses giving classic $9:3:3:1$ phenotypic ratios for unlinked heterozygous parents).
Probability Rule: The probability of offspring inheriting dual maternal and paternal alleles is the product of independent gamete probabilities: $P(A_1 A_2) = P(A_1) \times P(A_2)$.
Operating Instructions: Select Monohybrid or Dihybrid mode, enter maternal/paternal parental genotypes, and generate cross matrices and ratios.