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.
A particularly important category of genetic linkage has to do with the X and Y sex chromosomes. These not only carry the genes that determine male and female traits but also those for some other characteristics as well. Genes that are carried by either sex chromosome are said to be sex linked. Men normally have an X and a Y combination of sex chromosomes, while women have two X's. Since only men inherit Y chromosomes, they are the only ones to inherit Y-linked traits.