Final answer:
In genetic inheritance, two gametes have a 25 percent chance to unite during random mating, which is based on Mendel's principles of random segregation resulting in a 1:2:1 genotypic ratio.
Step-by-step explanation:
When modeling random mating involving genetic inheritance and the formation of gametes, it's important to apply Mendel's principles of heredity. For two heterozygous individuals (Aa), the probability that two gametes, each carrying one allele from a parent, unite to form an offspring with each possible genotype is equally likely. Mendel's principle of random segregation leads to the possible combinations of AA, Aa (or aA), and aa. Assuming a random union of gametes, each offspring has a 25 percent chance of receiving each of these genotypic combinations. Therefore, the probability that two gametes unite is most accurately represented by option C) 0.25 or a 25 percent chance.