Final answer:
Continuous characteristics cannot display Mendelian ratios because they are influenced by multiple genes, leading to a gradient of phenotypes within a population, unlike the clear-cut Mendelian traits observed by Mendel.
Step-by-step explanation:
In analyzing continuous characteristics, one cannot observe Mendelian ratios. The reason for this is that continuous characteristics are determined by the collective effect of multiple genes, known as polygenes, and environmental factors, leading to a range of continuous variation within a population. Unlike the traits studied by Gregor Mendel which showed discontinuous variation with clear-cut phenotypic differences inherited in predictable ratios, continuous variations such as human height or skin color do not produce simple Mendelian ratios because they result from the action of many genes, which creates a gradient of phenotypes. This is also why offspring appear as a "blend" of their parents' traits for such characteristics.