Gregor Mendel's experiments disproved the idea that offspring are simply a blend of their parents' traits-known as the blending theory of inheritance-by demonstrating that traits are inherited as discrete units, now known as genes, which maintain their identity across generations.

How Mendel Disproved Blended Inheritance

• Discrete Traits Instead of Blends : Mendel observed that when he crossed pea plants with contrasting traits (e.g., tall vs. short), the first generation (F1) offspring all exhibited only one of the parental traits (the dominant trait), rather than an intermediate blend. For example, crossing tall and short plants produced all tall offspring, not medium-height plants

• Reappearance of Recessive Traits : When Mendel allowed the F1 generation to self-fertilize, the recessive trait (e.g., shortness) reappeared in the second generation (F2) in a predictable ratio of about 3 dominant to 1 recessive. This showed that the recessive trait was not lost or blended away but was hidden in the F1 and re-emerged intact

• Law of Segregation : Mendel concluded that each trait is controlled by two "factors" (now called alleles), one inherited from each parent, which segregate during the formation of sex cells so that each gamete carries only one allele. The offspring thus inherit one allele from each parent, preserving the distinct identity of traits rather than blending them

• Law of Independent Assortment : Mendel also showed that different traits are inherited independently of each other, meaning the inheritance of one trait does not affect the inheritance of another. This further contradicted blending inheritance, which would predict a uniform mixing of all traits

Summary

Mendel's careful and mathematically analyzed experiments with thousands of pea plants demonstrated that inheritance follows specific patterns governed by discrete units (genes), not by the blending of parental traits. This explained phenomena such as traits skipping generations and offspring showing traits not visible in either parent, which the blending theory could not account for

. Thus, Mendel's work laid the foundation for modern genetics by showing that traits are inherited as distinct, particulate units rather than as blended mixtures of parental characteristics.