ABSTRACT
The genome is the full complement of genetic information in a cell, and contains the ‘program’ required for that cell to function. It can be thought of as either the total genetic material or, where there is more than one copy of the same information, the genetic material comprising a single copy of that information (the latter is sometimes termed the haploid genome). The number of redundant copies of the genome in the cell is its ploidy. In eukaryotes, over 99% of cellular DNA is found in the nuclear genome, but DNA is also found in organelles (see Organelle Genomes). Bacterial and organelle genomes are small and are usually single, circular chromosomes, although some linear bacterial genomes have been reported. Eukaryote nuclear genomes are comparatively very large and are split into multiple, linear chromosomes. Viruses show great diversity in genome structure (for discussion, see Viruses).
