Final answer:
Pleiotropy involves a single gene causing multiple effects, whereas polygenic inheritance includes multiple genes contributing to a single characteristic. Examples of polygenic traits include height and skin color, which exhibit a range of variations.
Step-by-step explanation:
Pleiotropy and polygenic inheritance are two different aspects of genetic expression in biology. Pleiotropy refers to a situation where a single gene can exhibit multiple expressions or have multiple effects on the phenotype. This is different from polygenic inheritance, where multiple genes control a single characteristic. Polygenic inheritance can be identified in traits that show a range of variations, such as height and skin color, and these traits can often be measured and exhibit variability influenced by environmental factors.
In summary, pleiotropy describes the effect of one gene affecting multiple traits, while polygenic inheritance involves several genes contributing to a single trait. The key difference is whether a single gene or multiple genes are influencing the phenotypic outcome.