Which term describes patterns of inheritance that do not follow Mendel's laws, such as incomplete dominance, codominance, multiple alleles, polygenic traits, or sex-linked traits?

• A. Codominance
• B. Incomplete dominance
• C. Non-Mendelian inheritance
• D. Multiple allele traits

Answer: (C)

Patterns of inheritance that do not follow Mendel's laws are described by non-Mendelian inheritance. Mendel’s rules work well for simple traits controlled by a single gene with two alleles and clear dominant-recessive relationships, predicting specific ratios like 3:1 or 1:2:1. But many genetic patterns deviate from that simple picture: incomplete dominance where the heterozygote shows an intermediate phenotype, codominance where both alleles are expressed simultaneously, multiple alleles where more than two alleles influence the trait, and polygenic traits where many genes contribute to a continuous range of phenotypes. Sex-linked traits, tied to genes on the sex chromosomes, also produce inheritance patterns that differ from Mendel’s expectations. Together, these examples fall under non-Mendelian inheritance, the umbrella term for patterns that don’t follow Mendel’s classic rules.