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Ricin (/ ˈ r aɪ s ɪ n / RY-sin) is a lectin (a carbohydrate-binding protein) and a highly potent toxin produced in the seeds of the castor oil plant, Ricinus communis.The median lethal dose (LD 50) of ricin for mice is around 22 micrograms per kilogram of body weight via intraperitoneal injection.
Biosynthesis, i.e., chemical synthesis occurring in biological contexts, is a term most often referring to multi-step, enzyme-catalyzed processes where chemical substances absorbed as nutrients (or previously converted through biosynthesis) serve as enzyme substrates, with conversion by the living organism either into simpler or more complex ...
Ecopsychology is an interdisciplinary and transdisciplinary field that focuses on the synthesis of ecology and psychology and the promotion of sustainability. [1] [2] [3] It is distinguished from conventional psychology as it focuses on studying the emotional bond between humans and the Earth.
Land, unlike the ocean, is not continuous; there are important geographical barriers to free movement. The nature of the substrate, although important in water is especially vital in terrestrial environment. Soil, not air, is the source of highly variable nutrients; it is a highly developed ecological subsystem.
Since ricin is a protein, antibodies may be produced by inoculation, allowing resistance of up to 800 times a normal lethal dose. Ricin has been used in assassinations, a notorious case being the use of a 1.53 mm pellet holding a few hundred millionths of a gram of ricin to kill the Bulgarian broadcaster, Georgi Markov , who died 4 days after ...
The rhizosphere is the thin area of soil immediately surrounding the root system. It is a densely populated area in which the roots compete with invading root systems of neighboring plant species for space, water, and mineral nutrients as well as form positive and negative relationships with soil-borne microorganisms such as bacteria, fungi and insects.
Ricinoleic acid, formally called 12-hydroxy-9-cis-octadecenoic acid, is a fatty acid.It is an unsaturated omega-9 fatty acid [1] and a hydroxy acid.It is a major component of the seed oil obtained from the seeds of castor plant (Ricinus communis L., Euphorbiaceae), the plant that produces ricin.
It can often be difficult in practice to distinguish allelopathy from resource competition. While the former is caused by the addition of a harmful chemical agent to the environment, the latter is caused by the removal of essential resources (nutrients, light, water, etc.). Often, both mechanisms can act simultaneously.