Polygenic inheritance and Mendelian inheritance represent two distinct mechanisms through which traits are transmitted from parents to their offspring.

Mendelian inheritance, named after the scientist and monk Gregor Mendel, is characterized by the influence of a single gene on a specific trait. Mendel’s pioneering experiments with pea plants led to the formulation of this inheritance model. He discovered that certain traits, such as flower color and seed shape, are dictated by individual genes that have multiple variations, known as ‘alleles’. These alleles can be categorized as dominant or recessive, and the specific combination of alleles inherited from the parents determines the observable traits, or phenotypes, of an organism.

In contrast, polygenic inheritance involves the interplay of multiple genes to influence a single trait. In this case, the trait is not controlled by just one gene but is the result of the cumulative effects of several genes. Traits associated with polygenic inheritance include characteristics such as height, skin color, and eye color. Because these traits are governed by multiple genes, each capable of existing in various forms, they exhibit a broad spectrum of variation. This results in continuous phenotypic ranges, as opposed to the distinct categories typically observed in Mendelian inheritance.

Additionally, environmental factors significantly impact traits governed by polygenic inheritance. For instance, an individual’s height is affected not only by their genetic makeup but also by external factors such as nutrition and overall health during their growth phase. This complexity makes predicting outcomes in polygenic inheritance more challenging compared to Mendelian inheritance.

In summary, Mendelian inheritance is defined by the influence of single genes on individual traits, while polygenic inheritance involves the contributions of multiple genes to a single trait. As polygenic traits often exhibit wide variations and are susceptible to environmental influences, they present a more intricate pattern of inheritance than those observed in Mendelian traits.