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A simplified Jablonski diagram illustrating the change of energy levels.. The principle behind fluorescence is that the fluorescent moiety contains electrons which can absorb a photon and briefly enter an excited state before either dispersing the energy non-radiatively or emitting it as a photon, but with a lower energy, i.e., at a longer wavelength (wavelength and energy are inversely ...
At these depths of the aphotic zone, the only sources of light are organisms themselves, giving off light through chemical reactions in a process called bioluminescence. Fluorescence is simply defined as the absorption of electromagnetic radiation at one wavelength and its reemission at another, lower energy wavelength. [ 33 ]
The elongate jewel squid (Histioteuthis reversa), so called because the photophores festooning its body make it appear bejewelled. Diagram of a cephalopod's photophore, in vertical section. A photophore is a glandular organ that appears as luminous spots on marine animals, including fish and cephalopods. The organ can be simple, or as complex ...
Typically quinine fluoresces blue, which is visible in the right sample. The left sample contains chloride ions which quench quinine's fluorescence, so the left sample does not fluoresce visibly (the violet light is just scattered laser light). In chemistry, quenching refers to any process which decreases the fluorescent intensity of a given ...
Sometimes blood flowing from other sources of bleeding passes through the nasal cavity and exits the nostrils. It is thus blood coming from the nose but is not a true nosebleed, that is, not truly originating from the nasal cavity. Such bleeding is called "pseudoepistaxis" (pseudo + epistaxis).
Growth towards a light source is called positive phototropism, while growth away from light is called negative phototropism. Negative phototropism is not to be confused with skototropism, which is defined as the growth towards darkness, whereas negative phototropism can refer to either the growth away from a light source or towards the darkness ...
The sources of energy can be light or chemical compounds; the sources of carbon can be of organic or inorganic origin. [ 1 ] The terms aerobic respiration , anaerobic respiration and fermentation ( substrate-level phosphorylation ) do not refer to primary nutritional groups, but simply reflect the different use of possible electron acceptors in ...
Bleeding, hemorrhage, haemorrhage or blood loss is blood escaping from the circulatory system from damaged blood vessels. [1] Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethra, vagina or anus, or through a puncture in the skin.