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Biogenetically, there are several proven pathways for the formation of the quinoline system in plants. Tryptophane as well as anthranilic acid can act as a precursor. The second precursor molecule is either a hemiterpene or a monoterpene (e.g. secologanine in cinchona alkaloids).
Raunkiær's life-form scheme has subsequently been revised and modified by various authors, [6] [7] [8] but the main structure has survived. Raunkiær's life-form system may be useful in researching the transformations of biotas and the genesis of some groups of phytophagous animals.
where ε r is the dielectric constant of the dispersion medium, ε 0 is the permittivity of free space (C 2 N −1 m −2), η is dynamic viscosity of the dispersion medium (Pa s), and ζ is zeta potential (i.e., the electrokinetic potential of the slipping plane in the double layer, units mV or V).
The sperm of members from the genus are large, as is typical of cycads, and Z. roezlii is an example; its sperm are approximately 0.4 mm long and can be seen by the unaided eye. [11] It was long believed that Zamia plants, like all cycads, relied completely on wind pollination.
Santalales is ecologically diverse and includes free-living plants, such as Erythropalum, as well as (hemi)parasites. Among the latter are species that parasitize stems or shoots, such as the mistletoes of the genus Misodendrum , and root parasites, including the well-known and economically important sandalwood tree ( Santalum album ), whose ...
Stentor coeruleus, used in molecular biology (its genome has been sequenced), [5] and is studied as a model of single-cell regeneration.; Dictyostelium discoideum, used in molecular biology and genetics (its genome has been sequenced), and is studied as an example of cell communication, differentiation, and programmed cell death.
The two main mechanisms causing damage to recalcitrant seeds are desiccation effects on the intracellular structures and metabolic damage from the formation of toxic chemicals such as free radicals. [5] An example of the first type of damage would be found in some recalcitrant nontropical hardwood seeds, specifically the acorns of recalcitrant ...
Associations between fungi and plant roots, wherein the fungus facilitates nutrient uptake (particularly nitrogen) by the plant in exchange for carbon in the form of sugars from the plant root. [2] There is a parallel example in marine environments of sponges on the roots of mangroves, with a relationship analogous to that of mycorrhizae and ...