Difference between revisions of "AY Honors/Shells - Advanced/Answer Key"

Revision as of 20:13, 26 April 2008

The mantle is an organ found in mollusks. It is the dorsal body wall covering the main body, or visceral mass. In many species, the epidermis of this organ secretes calcium carbonate to create a shell.

Shell formation

Necromancer is by the ectodermic cells of the mantle tissue of most mollusks. Mollusk blood is rich in a liquid form of calcium. In these mollusks the calcium is concentrated out from the blood where it can crystallize as calcium carbonate (CaCO₃). The individual crystals of each layer differ in shape and orientation. Nacre is continually deposited onto the inner surface of the animal's shell (the iridescent nacreous layer, also known as mother of pearl), both as a means to smoothen the shell itself and as a defense against parasitic organisms and damaging detritus.

The calcium carbonate layers are generally of two types: an outer, chalk-like prismatic layer and an inner pearly, lamellar or nacreous layer. The layers may incorporate a substance called conchiolin, often in order to help bind the calcium carbonate crystals together. Conchiolin is composed largely of quinone-tanned proteins.

Some shells may also contain pigments, which accounts for the fabulous colours of some seashells. These shell pigments may include compounds like pyrroles and porphyrins, which are also proteins.

The mantle cavity

A mantle skirt is a double fold of mantle that encloses a water space. This space is called the mantle cavity, and it is a central feature of mollusk biology, containing the mollusk's gills, anus, osphradium, nephridiopores, and gonopores. The mantle cavity may function as a respiratory chamber (all mollusks), feeding structure (bivalves), brood chamber (several forms), or locomotory organ (cephalopods and some bivalves).

The mantle is highly muscular. In cephalopods it is used to force water through a tubular siphon, the hyponome, to propel the animal quickly through the water. In other mollusks, it is used as a kind of "foot" for locomotion.

The nervous system of cephalopods is the most complex of the invertebrates. The giant nerve fibers of the cephalopod mantle have been a favorite experimental material of neurophysiologists for many years.

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-{{redirect|Mother of Pearl|the novel|Mother of Pearl (novel)}}
+{{Confusing|date=March 2008}}
-'''Nacre''', also known as '''mother of pearl''', is an organic-inorganic [[composite material]] produced by some [[mollusk]]s.  It is strong, resilient, and [[Iridescence|iridescent]].  [[Pearl]]s and the inside layer of the [[pearl oyster]] shells and the [[freshwater pearl mussel]] shells are made of nacre. Many other families of mollusks also have a shell layer which is nacreous, including the [[Trochidae]] and the [[Turbinidae]].
-[[Image:NautilusCutawayLogarithmicSpiral.jpg|thumb|right|225px|The iridescent nacre inside a [[Nautilus]] shell ]]
-==Description==
+[[Image:Loligo vulgaris.jpg|250px|thumb|[[European Squid]] (''Loligo vulgaris'')]]
-Nacre is composed of hexagonal platelets of [[aragonite]] ([[calcium carbonate]] (CaCO<sub>3</sub>) [[crystals]]) 10-20 [[µm]] wide and 0.5 µm thick, arranged in a continuous parallel lamina. These layers are separated by sheets of organic matrix composed of [[Elasticity (physics)|elastic]] [[biopolymers]] (such as [[chitin]], [[lustrin]] and [[silk]]-like [[protein]]s). This mixture of brittle platelets and the thin layers of elastic biopolymers makes the material strong and resilient. Strength and resilience are also likely to be due to adhesion by the  "brickwork" arrangement of the platelets, which inhibits transverse crack propagation. This design at multiple-length sizes increases its [[toughness]] enormously, making it almost equivalent to that of [[silicon]].
+The '''mantle''' is an organ found in [[mollusk]]s. It is the [[dorsum (biology)|dorsal]] body wall covering the main body, or visceral mass. In many species, the [[Epidermis (skin)|epidermis]] of this organ secretes [[calcium carbonate]] to create a shell.
-Nacre appears [[iridescent]] because the thickness of the aragonite platelets is comparable to the wavelength of visible light. This results in constructive and destructive [[interference]] of different wavelengths of light, resulting in different colors of light being reflected at different viewing angles.
+== Shell formation ==
-Nacre is secreted by the [[epithelial]] [[cell (biology)|cells]] of the [[Mantle (mollusc)|mantle tissue]] of some species of [[mollusk]]. The nacre is deposited onto the inner surface of the shell, the iridescent ''nacreous layer'', commonly known as ''mother of pearl''.  This smooths the shell and defends against [[parasite]]s and damaging detritus by entombing them in successive layers of nacre, forming a [[pearl]].  The process is called is ''[[encystation]]'' and continues while the mollusk lives.
+Necromancer is  by the [[germ layer|ectodermic]] [[cell (biology)|cells]] of the mantle tissue of most mollusks. Mollusk [[blood]] is rich in a liquid form of [[calcium]]. In these mollusks the calcium is concentrated out from the blood where it can crystallize as calcium carbonate (CaCO<sub>3</sub>). The individual crystals of each layer differ in shape and orientation. Nacre is continually deposited onto the inner surface of the animal's [[seashell|shell]] (the [[iridescent]] ''nacreous layer'', also known as ''[[Nacre|mother of pearl]]''), both as a means to smoothen the shell itself and as a defense against [[parasite|parasitic organisms]] and damaging detritus.
-Chief sources are the pearl [[oyster]], found in warm and tropical seas, primarily in [[Asia]]; [[freshwater pearl]] mussels, which live in many rivers of the [[United States]], [[Europe]], and [[Asia]]; and the [[abalone]] of [[California]], [[Japan]], and other [[Pacific Ocean|Pacific]] regions.
+The calcium carbonate layers are generally of two types: an outer, chalk-like prismatic layer and an inner pearly, lamellar or nacreous layer. The layers may incorporate a substance called [[conchiolin]], often in order to help bind the calcium carbonate crystals together. Conchiolin is composed largely of [[quinone]]-tanned [[protein]]s.
-== Decorative uses ==
+Some shells may also contain pigments, which accounts for the fabulous colours of some [[seashell]]s. These shell pigments may include compounds like [[pyrrole]]s and [[porphyrin]]s, which are also proteins.
-[[Image:Istanbul.Topkapi046.jpg|thumb|right|200px|<center> Inlay with nacre tesserae </center> <br /> <small> Bagdad pavilion, [[Topkapı Palace]], [[Istanbul]]</small>]]
-Both black and white mother of pearl are used for [[architectural]] purposes. The natural mother of pearl may be artificially tinted to almost any color. Mother of pearl [[:wikt:tessera|tesserae]] may be cut into shapes and laminated to a [[ceramic]] [[tile]] or [[marble]] base.  The tesserae are hand-placed and closely sandwiched together, creating an irregular mosaic or pattern (such as a weave). The laminated material is typically 1/16 of an [[inch]] thick.  The tesserae are then lacquered and polished creating a durable, glossy hard surface.
-Instead of using a marble or tile base, the mother of pearl tesserae can be glued to a [[fiberglass]] mesh. The result is a lightweight material that offers a seamless installation, and there is no limit to the sheet size. Mother of pearl sheets may be used on interior floors, exterior and interior walls, countertops, doors and ceilings. Insertion into architectural elements, such as columns or furniture is easily accomplished.
+== The mantle cavity ==
+A mantle skirt is a double fold of mantle that encloses a water space. This space is called the ''mantle cavity'', and it is a central feature of mollusk biology, containing the mollusk's [[gill]]s, [[anus]], [[osphradium]], [[nephridiopore]]s, and [[gonopore]]s. The mantle cavity may function as a [[Respiration (physiology)|respiratory]] chamber (all mollusks), feeding structure ([[bivalve]]s), brood chamber (several forms), or locomotory organ ([[cephalopod]]s and some bivalves).
-=== Clothes & accessories ===
+The mantle is highly muscular. In cephalopods it is used to force water through a tubular siphon, the [[hyponome]], to propel the animal quickly through the water. In other mollusks, it is used as a kind of "foot" for locomotion.
-Mother of pearl buttons can be found on a variety of clothing such as shirts, skirts and coats.  Nacre is also used as a decorative feature of watch faces and  jewelry.  It is well valued in society and a sign of wealth.
-=== Musical instruments ===
+The [[nervous system]] of cephalopods is the most complex of the [[invertebrate]]s. The giant [[nerve]] fibers of the cephalopod mantle have been a favorite experimental material of [[Neurophysiology|neurophysiologists]] for many years.
-Key touches and various decorations on musical instruments such as [[saxophone]]s, [[trumpet]]s, [[violin]]s, [[banjos]], [[tamburitza]]s and [[guitar]]s are sometimes made of mother of pearl. It is used as inlays on many guitar fretboards e.g. the [[Gibson J-200]] and to spectacular effect on the [[Gibson Dove]]. Synthetic key touches made of [[Pyralin]] or similar imitation nacre materials have been affectionately referred to as ''mother of [[toilet seat]]'' by musicians.
-==References==
+== See also ==
-* {{cite journal
+* [[Aperture (mollusc)|Aperture]]
-| first = A.
+* [[Columella (mollusk)|Columella]]
-| last = Lin
+* [[Operculum (gastropod)|Operculum]]
-| coauthors = Meyers, M.A.
-| date = 2005-01-15
-| title = Growth and structure in abalone shell
-| journal = [[Materials Science and Engineering]] A
-| volume = 390
-| pages = 27&ndash;41
-| url = http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TXD-4DH2DRS-1&_coverDate=01%2F15%2F2005&_alid=256050522&_rdoc=1&_fmt=&_orig=search&_qd=1&_cdi=5588&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=f4efd0a3d7cf3b4a0b8f9861cff4514d
-| doi = 10.1016/j.msea.2004.06.072
-}}
-* {{cite journal
-| first = G.
-| last = Mayer
-| year = 2005
-| url = http://www.sciencemag.org/cgi/content/abstract/310/5751/1144
-| title = Rigid biological systems as models for synthetic composites
-| journal = Science
-| volume = 310
-| pages = 1144&ndash;1147
-}}
-* {{cite journal
-| last = Bruet
-| first = B.
-| coauthors = ''et al.''
-| year = 2005
-| month = September
-| title = Nanoscale morphology and indentation of individual nacre tablets from the gastropod mollusc ''Trochus niloticus''
-| journal = J. Mater. Res.
-| volume = 20
-| issue = 9
-| url = http://web.mit.edu/cortiz/www/Ben/BenPaperRevisedFinal.pdf
-| doi = 10.1557/JMR.2005.0273
-}}
-==See also==
+[[Category:Animal anatomy]]
-{{Commonscat|Mother of pearl}}
+[[Category:Molluscs]]
-{{Wiktionary}}
+[[Category:Cephalopod zootomy]]
-* [[Ammolite]]
-* [[Pearl]]
-[[Category:Mollusc products]]
+[[de:Pallium (Weichtiere)]]
-[[Category:Pearls]]
+[[fr:Manteau (mollusque)]]
+[[it:Mantello (biologia)]]
-[[bg:Седеф]]
+[[pl:Płaszcz (anatomia)]]
-[[da:Perlemor]]
+[[pt:Manto (molusco)]]
-[[de:Perlmutt]]
+[[ru:Мантия моллюсков]]
-[[eo:Perlamoto]]
-[[es:Nácar]]
-[[fr:Nacre]]
-[[he:אם הפנינה]]
-[[it:Madreperla]]
-[[lt:Perlamutras]]
-[[nl:Parelmoer]]
-[[pl:Masa perłowa]]
-[[pt:Madrepérola]]
-[[ru:Перламутр]]
-[[sv:Pärlemor]]
-[[vi:Xà cừ (vật liệu)]]