Final answer:
In a trihybrid cross with parental genotypes AaBbCc, there are 27 possible genotypes and 8 possible phenotypes when traits behave in a dominant and recessive pattern.
Step-by-step explanation:
In a trihybrid cross between two parents heterozygous for all three genes (AaBbCc), and when the genes sort independently following a dominant and recessive pattern, we expect different outcomes for genotypes and phenotypes. For genotypes, each gene can have 3 possible combinations (AA, Aa, aa), and with three genes, we calculate the number of genotypic combinations by raising 3 to the power of 3 (3 genes), which results in 33 or 27 possible genotypes. For phenotypes, each trait can have 2 possible outcomes (either dominant or recessive), and there are 3 traits in a trihybrid cross, so we calculate the phenotypic combinations by raising 2 to the power of 3, resulting in 23 or 8 possible phenotypes. Therefore, the correct answer is 27 genotypes; 8 phenotypes.