Final answer:
Pleiotropy is the term for a single gene influencing multiple traits. It differs from polygenic traits, which involve multiple genes, and also from polymorphic traits, which involve different forms of a gene within a population.
Step-by-step explanation:
The name given to a single gene which determines several different traits is pleiotropy. Unlike polygenic traits which are traits controlled by more than one gene, pleiotropy refers to the phenomenon where one gene may influence multiple, seemingly unrelated phenotypic traits. This is different from traits described as being polymorphic, which implies the existence of multiple forms (alleles) within a population that may result in different phenotypes. A dominant allele is one that can determine the phenotype even in the presence of a different allele, while in contrast, wild-type refers to the most common phenotype or genotype observed in the natural population.
It's essential to note that most human characteristics, such as height or weight, are polygenic and can be influenced by environmental factors. This genetic diversity is crucial for the survival of species. In the case of multiple alleles, such as the ABO blood type system, there are more than two alleles present at the population level, but an individual can only have two of them. This depicts the complexity of inheritance patterns beyond simple Mendelian genetics.