Transduction is the transfer of host DNA from one cell to another by a virus. Some bacteriophages are temperate since they tend to go lysogenic rather than lytic. Image from W.H. Freeman and Sinauer Associates, used by permission. Unlike episomes and prophages, transposons contain a gene producing an enzyme that catalyzes insertion of the transposon at a new site. They also have repeated sequences 20-40 nucleotides in length at each end.
Complex transposons are much larger and carry additional genes.
Often the complex transposons are flanked by simple transposons. Image from W.H. Freeman and Sinauer Associates, used by permission. The eukaryotic chromosome consists of DNA and proteins that appear to play a major role in regulation of eukaryote genes. Eukaryotic DNA comes in two forms. The proteins associated with DNA are collectively known as histones .