material entity material entity material genome physical genome A material entity that represents all genetic material in a cell or virion. The material genome is typically molecular aggregate of all the chromosomal DNA and epi-chromosomal DNA that represents all sequences that are heritable by progeny of a cell or virion. A genome is the collection of all nucleic acids in a cell or virus, representing all of an organism's hereditary information. It is typically DNA, but many viruses have RNA genomes. The genome includes both nuclear chromosomes (ie nuclear and micronucleus chromosomes) and cytoplasmic chromosomes stored in various organelles (e.g. mitochondrial or chloroplast chromosomes), and can in addition contain non-chromosomal elements such as replicative viruses, plasmids, and transposable elements. Note that at present, a material genome and genetic material are necessarily part of some cell or virion. So a genomic library is not considered a material genome/genetic material - rather, we could say that this genomic library is a 'genomic material sample' that bears the concretization of some SO:genome.