Visual binary Visual binary A visual binary is a gravitationally bound system that can be resolved into two stars. These stars are estimated, via Kepler's 3rd law, to have periods ranging from a number of years to thousands of years. A visual binary consists of two stars, usually of a different brightness. Because of this, the brighter star is called the primary and the fainter one is called the companion. If the primary is too bright, relative to the companion, this can cause a glare making it difficult to resolve the two components. However, it is possible to resolve the system if
Transfer DNA binary system Transfer DNA binary system A transfer DNA (T-DNA) binary system is a pair of plasmids consisting of a binary plasmid and a helper plasmid. The two plasmids are used together (thus "binary") to produce genetically modified plants. They are artificial vectors that have both been created from the naturally occurring Ti plasmid found in "Agrobacterium tumefaciens". The binary vector is a "shuttle vector", so-called because it is able to replicate in multiple hosts ("E. coli" and "Agrobacterium tumefaciens"). Systems in which T-DNA and vir genes are located on separate replicons are called T-DNA binary systems. T-DNA is located on the