Barr body. Definition. noun. The small, dark-staining mass of inactive X chromosome within the nucleus of non-dividing cell. Supplement. Barr bodies are previously used as the basis for sex determination especially during the Olympics (see Barr test). Word origin: named after its discoverer Murray Llewellyn Barr, a Canadian anatomist who first identified the particle in the nucleus of neurons of female cats. Synonym: sex chromatin.
As of September 2011, there are nine Unified Combatant Commands as specified in Title 10 and the latest annual UCP. Six have regional responsibilities, and three have functional responsibilities.
Descriptions of FPCONs. There are five Force Protection Conditions; the commander of U.S. Northern Command determines what the minimum force protection level will be for every American installation in the continental United States.