Arabidopsis thaliana is a small flowering plant that is widely used as a model organism in plant biology. Arabidopsis is a member of the mustard (Brassicaceae) family, which includes cultivated species such as cabbage and radish. Arabidopsis is not of major agronomic significance, but its small genome size and ease of cultivation offer important advantages for basic research in genetics and molecular biology. Arabidopsis has a genome size of approximately 135 Mb, and a haploid chromosome number of five.