Phenotypic Variation

The traits shown by an organism is it's phenotype. 

• Qualititative differences fall into clearly distinguishable categories, with no intermediates. Discontinous variation (blood groups)
• Quantitative traits have no distinguishable categories but instead a range of values. Continous variation (height or mass)

In discontinous (qualitative):

• different alleles at a single gene locus have large effects
• different gene loci have different effects on…