Asexual reproduction is a mode of reproduction by which offspring arise from a single organism, and inherit the genes of that parent only; it is reproduction which almost never involves ploidy or reduction. The offspring will be exact genetic copies of the parent, except in the specific case of automixis. A more stringent definition is agamogenesis which is reproduction without the fusion of gametes. Asexual reproduction is the primary form of reproduction for single-celled organisms such as the archaebacteria, eubacteria, and protists. Many plants and fungi reproduce asexually as well.