A SEP IRA (Simplified Employee Pension) is a retirement plan that is popular with many small business owners and self employed individuals. The 2015 SEP IRA contribution limit is $53,000 (the 2014 SEP limit is $52,000).
Meanwhile, other studies suggest that another gene, DRD4, may also play a role in traits such as shyness and anxiety. The DRD4 gene codes for a protein that binds dopamine, another chemical messenger that has powerful effects in the brain. Again, the DRD4 gene comes in two forms: a long and a short version.
Running the Gamut. Multiple genes and, therefore, multiple alleles, affect continuous, or quantitative, traits. Because they are caused by more than one gene, they are also referred to as polygenic traits. Gene expression is complex, and continuous traits can also be influenced by environmental factors. Continuous traits are common in humans, who show a wide range of possibilities in characteristics such as height, skin color, learning ability and blood pressure.