In the fields of molecular biology and genetics, a genome is the genetic material of an organism. It consists of DNA. The genome includes both the genes and the noncoding DNA, as well as mitochondrial DNA and chloroplast DNA. The study of the genome is called genomics.
Symbiogenesis, or endosymbiotic theory, is an evolutionary theory of the origin of eukaryotic cells from prokaryotic organisms, first articulated in 1905 and 1910 by the Russian botanist Konstantin Mereschkowski, and advanced and substantiated with microbiological evidence by Lynn Margulis in 1967. It holds that the organelles distinguishing eukaryote cells evolved through symbiosis of individual single-celled prokaryotes . The theory holds that mitochondria, plastids such as chloroplasts, and possibly other organelles of eukaryotic cells represent formerly free-living prokaryotes taken one inside the other in endosymbiosis. In more detail, mitochondria appear to be related to Rickettsiales proteobacteria, and chloroplasts to nitrogen-fixing filamentous cyanobacteria. Among the many lines of evidence supporting symbiogenesis are that new mitochondria and plastids are formed only through binary fission, and that cells cannot create new ones otherwise; that the transport proteins called porins are found in the outer membranes of mitochondria, chloroplasts and bacterial cell membranes; that cardiolipin is found only in the inner mitochondrial membrane and bacterial cell membranes; and that some mitochondria and plastids contain single circular DNA molecules similar to the chromosomes of bacteria.
Mitochondrial DNA is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, adenosine triphosphate (ATP). Mitochondrial DNA is only a small portion of the DNA in a eukaryotic cell; most of the DNA can be found in the cell nucleus and, in plants and algae, also in plastids such as chloroplasts.
Giardia is a genus of anaerobic flagellated protozoan parasites of the phylum metamonada that colonise and reproduce in the small intestines of several vertebrates, causing giardiasis. Their life cycle alternates between a swimming trophozoite and an infective, resistant cyst. Giardia were first described by the Dutch microscopist Antonie van Leeuwenhoek in 1681. The genus is named after French zoologist Alfred Mathieu Giard.
The gastropods, more commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca, called Gastropoda. This class comprises snails and slugs from saltwater, from freshwater, and from the land. There are many thousands of species of sea snails and slugs, as well as freshwater snails, freshwater limpets, and land snails and slugs.
Opisthobranchs is now an informal name for a large and diverse group of specialized complex gastropods which used to be united in the subclass Opisthobranchia. That taxon is no longer considered to represent a monophyletic grouping.
Fas-activated serine/threonine kinase is an enzyme that in humans is encoded by the FASTK gene.
Myosotella myosotis, common name the mouse ear snail, is a European species of small, salt marsh snail, a terrestrial pulmonate gastropod mollusk in the family Ellobiidae.
Apogastropoda was previously used as a major taxonomic grouping of sea snails, marine gastropod molluscs. This infraclass mostly consisted of marine limpets and operculate snails. At least 20,000 species were considered to exist within the two clades that were included, Heterobranchia and Caenogastropoda.
Vetigastropoda is a major taxonomic group of sea snails, marine gastropod mollusks that form a very ancient lineage. Taxonomically the Vetigastropoda are sometimes treated as an order, although they are treated as an unranked clade in Bouchet and Rocroi, 2005.
Euthyneura is a taxonomic clade of snails and slugs, which includes species from freshwater, marine, aquatic and terrestrial gastropod mollusks in the clade Heterobranchia.
Jakobids are an order of free-living, heterotrophic, flagellar eukaryotes in the supergroup Excavata. They are small, and can be found in aerobic and anaerobic environments. The order Jakobida, believed to be monophyletic, consists of only twenty species at present, and was classified as a group in 1993. There is ongoing research into the mitochondrial genomes of jakobids, which are unusually large and bacteria-like, evidence that jakobids may be important to the evolutionary history of eukaryotes.
Pyramidella dolabrata, common name the "giant Atlantic pyram", is a somewhat variable species of small to medium-sized sea snail, a marine gastropod mollusk in the family Pyramidellidae, the pyram snails.
Siphonaria pectinata, common name the striped false limpet, is a species of air-breathing sea snail or false limpet, a marine heterobranch gastropod mollusc in the family Siphonariidae, the false limpets.
Cylindrobulla is a genus of sea snails or bubble snails, marine gastropod mollusks in the clade Sacoglossa.
Onchidella celtica is a species of air-breathing sea slug, a shell-less marine pulmonate gastropod mollusk in the family Onchidiidae.
This overview lists proposed changes in the taxonomy of gastropods at the family level and above since 2005, when the taxonomy of the Gastropoda by Bouchet & Rocroi (2005) was published. In other words, these are recent updates in the way various groups of snails and slugs are classified.
Sterkiella histriomuscorum, formerly Oxytricha trifallax, is a ciliate species in the genus Sterkiella, known for its highly fragmented genomes which have been used as a model for ciliate genetics.
Campodea fragilis is a species of two-pronged bristletail in the family Campodeidae.
