What is the difference between Mendelian and non-Mendelian inheritance?

Mendelian and non-Mendelian inheritance describe different patterns of how traits are passed from parents to offspring.

Mendelian inheritance follows the laws proposed by Gregor Mendel, where traits are controlled by single genes with clear dominant and recessive alleles.

Non-Mendelian inheritance includes patterns that do not follow Mendel’s laws, involving more complex genetic interactions.

Key differences:

• Basic principle:
  Mendelian: follows laws of dominance, segregation, and independent assortment
  Non-Mendelian: does not strictly follow these laws

• Gene control:
  Mendelian: one gene controls one trait
  Non-Mendelian: multiple genes or interactions may control a trait

• Allele interaction:
  Mendelian: complete dominance (one allele masks the other)
  Non-Mendelian: may involve incomplete dominance, codominance, multiple alleles, etc.

• Phenotypic ratios:
  Mendelian: predictable ratios like 3:1 or 9:3:3:1
  Non-Mendelian: ratios may vary and are less predictable

• Examples:
  Mendelian: pea plant height (tall vs dwarf)
  Non-Mendelian: blood group inheritance (ABO system), skin color

In simple terms: Mendelian inheritance follows simple genetic rules, while non-Mendelian inheritance involves more complex patterns of trait expression.