In humans, height shows a lot of variation. It is an example of

A.Multiple alleles - Presence of more than two alleles for a gene is called Mutliple alleles. These are present on the same locus of homologous chromosomes. eg: ABO blood group in Man

B.Pleiotropic inheritance ?  The ability of a gene to have a multiple phenotypic effects is known as pleiotrophy and the gene is called Pleiotropic gene and the inheritance is called Pleiotropic inheritance.

eg:Sickel cell anaemia

C.Polygenic inheritance ? Inheritance is controlled by two or more genes in which the dominant alleles have cumulative effect, with each dominant allele expressing a part of functional polypeptide and full trait is shown when all the dominant alleles are present, is called Polygenic or Quantitative inheritance. Eg:Human height, skin colour.

D.Pseudoalleles ? Genes are present together side by side and they produce related phenotypes are called pseudoalleles. These are distinguished from true alleles through rare crossing over.