part of part of in taxon cytoplasm mitochondrion A semiautonomous, self replicating organelle that occurs in varying numbers, shapes, and sizes in the cytoplasm of virtually all eukaryotic cells. It is notably the site of tissue respiration. GO:0005739 Some anaerobic or microaerophilic organisms (e.g. Entamoeba histolytica, Giardia intestinalis and several Microsporidia species) do not have mitochondria, and contain mitochondrion-related organelles (MROs) instead, called mitosomes or hydrogenosomes, very likely derived from mitochondria. To annotate gene products located in these mitochondrial relics in species such as Entamoeba histolytica, Giardia intestinalis or others, please use GO:0032047 'mitosome' or GO:0042566 'hydrogenosome'. (See PMID:24316280 for a list of species currently known to contain mitochondrion-related organelles.) NIF_Subcellular:sao1860313010 Wikipedia:Mitochondrion mitochondria cellular_component intracellular membrane-bounded organelle Eukaryota