SymbiosisSymbiosis (from Greek συμβίωσις, symbíōsis, "living together", from σύν, sýn, "together", and βίωσις, bíōsis, "living") is any type of a close and long-term biological interaction between two biological organisms of different species, termed symbionts, be it mutualistic, commensalistic, or parasitic. In 1879, Heinrich Anton de Bary defined it as "the living together of unlike organisms". The term is sometimes used in the more restricted sense of a mutually beneficial interaction in which both symbionts contribute to each other's support.
SymbiodiniumSymbiodinium is a genus of dinoflagellates that encompasses the largest and most prevalent group of endosymbiotic dinoflagellates known. These unicellular microalgae commonly reside in the endoderm of tropical cnidarians such as corals, sea anemones, and jellyfish, where the products of their photosynthetic processing are exchanged in the host for inorganic molecules. They are also harbored by various species of demosponges, flatworms, mollusks such as the giant clams, foraminifera (soritids), and some ciliates.
EndosymbiontAn endosymbiont or endobiont is any organism that lives within the body or cells of another organism most often, though not always, in a mutualistic relationship. (The term endosymbiosis is from the Greek: ἔνδον endon "within", σύν syn "together" and βίωσις biosis "living".) Examples are nitrogen-fixing bacteria (called rhizobia), which live in the root nodules of legumes, single-cell algae inside reef-building corals and bacterial endosymbionts that provide essential nutrients to insects.
BacterioplanktonBacterioplankton refers to the bacterial component of the plankton that drifts in the water column. The name comes from the Ancient Greek word πλανκτος (planktos), meaning "wanderer" or "drifter", and bacterium, a Latin term coined in the 19th century by Christian Gottfried Ehrenberg. They are found in both seawater and freshwater. Bacterioplankton occupy a range of ecological niches in marine and aquatic ecosystems. They are both primary producers and primary consumers in these ecosystems and drive global biogeochemical cycling of elements essential for life (e.
Host (biology)In biology and medicine, a host is a larger organism that harbours a smaller organism; whether a parasitic, a mutualistic, or a commensalist guest (symbiont). The guest is typically provided with nourishment and shelter. Examples include animals playing host to parasitic worms (e.g. nematodes), cells harbouring pathogenic (disease-causing) viruses, or a bean plant hosting mutualistic (helpful) nitrogen-fixing bacteria. More specifically in botany, a host plant supplies food resources to micropredators, which have an evolutionarily stable relationship with their hosts similar to ectoparasitism.
PhotosynthesisPhotosynthesis (ˌfoʊtəˈsɪnθəsɪs ) is a biological process used by many cellular organisms to convert light energy into chemical energy, which is stored in organic compounds that can later be metabolized through cellular respiration to fuel the organism's activities. The term usually refers to oxygenic photosynthesis, where oxygen is produced as a byproduct, and some of the chemical energy produced is stored in carbohydrate molecules such as sugars, starch and cellulose, which are synthesized from endergonic reaction of carbon dioxide with water.
C4 carbon fixationcarbon fixation or the Hatch–Slack pathway is one of three known photosynthetic processes of carbon fixation in plants. It owes the names to the 1960s discovery by Marshall Davidson Hatch and Charles Roger Slack that some plants, when supplied with 14, incorporate the 14C label into four-carbon molecules first. fixation is an addition to the ancestral and more common carbon fixation. The main carboxylating enzyme in photosynthesis is called RuBisCO, which catalyses two distinct reactions using either (carboxylation) or oxygen (oxygenation) as a substrate.
SymbiosomeA symbiosome is a specialised compartment in a host cell that houses an endosymbiont in a symbiotic relationship. The term was first used in 1983 to describe the vacuole structure in the symbiosis between the animal host the Hydra, and the endosymbiont Chlorella. Symbiosomes are also seen in other cnidaria-dinoflagellate symbioses, including those found in coral-algal symbioses. In 1989 the concept was applied to the similar structure found in the nitrogen-fixing root nodules of certain plants.
ReproductionReproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. Reproduction is a fundamental feature of all known life; each individual organism exists as the result of reproduction. There are two forms of reproduction: asexual and sexual. In asexual reproduction, an organism can reproduce without the involvement of another organism. Asexual reproduction is not limited to single-celled organisms.
Photosynthetic efficiencyThe photosynthetic efficiency is the fraction of light energy converted into chemical energy during photosynthesis in green plants and algae. Photosynthesis can be described by the simplified chemical reaction 6 H2O + 6 CO2 + energy → C6H12O6 + 6 O2 where C6H12O6 is glucose (which is subsequently transformed into other sugars, starches, cellulose, lignin, and so forth). The value of the photosynthetic efficiency is dependent on how light energy is defined – it depends on whether we count only the light that is absorbed, and on what kind of light is used (see Photosynthetically active radiation).
