The  first step in sequencing a genome is to divide the individual chromosomes (in eukaryotes) or whole DNA (in prokaryotes) in an ordered manner into smaller and smaller pieces that ultimately can be sequenced. That is, one begins by creating a genomic library of fragmented DNA parts. However, at some …

Each eukaryotic nucleus encloses a fixed number of chromosomes which contain the nuclear DNA. During most of a cell’s life, its chromosomes exist in a highly extended linear form. Prior to cell division, however, they condense into much more compact bodies which can be examined microscopically after staining. The duplication …

The genomes of viruses and prokaryotes are very simple structures, although those of viruses show remarkable diversity (for a review see Dimmock et al. 2001). Most viruses have a single linear or circular genome but a few, such as reoviruses, bacteriophage φ6 and some plant viruses, have segmented RNA genomes. …