Ans. While Mendel's principles of inheritance are generally accurate, there are a few exceptions to his conclusions. Some of these exceptions include incomplete dominance, codominance, multiple alleles, and sex-linked inheritance. Incomplete dominance occurs when neither allele is dominant, resulting in a blending of traits. Codominance refers to both alleles being expressed in the phenotype, leading to the presence of both traits. Multiple alleles occur when more than two alleles exist for a particular gene, and sex-linked inheritance involves genes located on the sex chromosomes.