Combinatorial number system 601 and 1010001011 = 651, which again shows that "C" comes before "C"<nowiki>'</nowiki>. This number is not however the one one wants to represent the "k"-combination with, since many binary numbers have a number of raised bits different from "k"; one wants to find the relative position of "C" in the ordered list of (only) "k"-combinations. The number associated in the combinatorial number system of degree "k" to a "k"-combination "C" is the number of "k"-combinations strictly less than "C" in the given ordering. This number can be computed from "C" = { "c", ..., "c", "c" } with "c"
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