In most multicellular organisms, every cell carries the same DNA, but this genetic information is used in varying ways by different types of cells. In other words, what a cell does within an organism dictates which of its genes are expressed.
Most enlisted positions require four years of active duty. If you join the Navy through an officer program, you must serve at least four of your eight years on active duty. However, pilots and flight officers must serve a minimum of eight to 10 years of active duty. Dentists, Medical Service Corps officers and nurses must serve a minimum of three years of active duty.
How long do they serve in the house of representatives? Members of the U.S. House of Representatives are elected for 2-year terms, so every two years each House seat is up for election. A member of the US House of Representatives serve a 2 year term of office; however a Representative has no limit on the number of terms he or she can serve.