The Deuteromycota are a form division, including those fungi in which sexual reproduction is unknown. They are also referred to in informal Latin as the Fungi imperfecti, and more recently as mitosporic fungi. This is a junk-basket category for forms of uncertain affinity, and is not treated formally in more recent systems, although it is still used widely by plant pathologists (see plant pathology) for the purposes of quick diagnosis and when the teleomorph stage of the particular organism is unknown. Because sexual reproduction is the basis for classification of fungi, it is often difficult to place these fungi in their appropriate group (because they lack sexual reproduction). The use of DNA-based technologies can often clarify their taxonomic relationships but can require extensive scientific efforts.