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

Revision as of 17:17, 5 March 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

Nacre 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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-{{honor_header|3|1949|Nature|General Conference}}
+{{cleanup-confusing}}
-==1. Have the Shell Honor. ==
+[[Image:Loligo vulgaris.jpg|250px|thumb|[[European Squid]] (''Loligo vulgaris'')]]
-{{Ay prerequisite|Nature|Shells}}
+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.
-==2. Define the term "mollusca" or "mollusk." ==
-==3. Learn the classification terms of mollusks, know the distinguishing characteristics of each, and become acquainted with several species under each class. ==
-==4 Distinguish between univalve and bivalve mollusks from the following considerations: ==
-===a. Shell   ===
-===b. Mollusk body  ===
-===c. Reproduction===
-===d. Movements===
-===e. Securing food===
-===f. Self-preservation===
-==5. Identify from shells or drawings and know the meaning of the following concho logical terms: ==
-===a. Valve  ===
-===b. Apex   ===
-===c. Aperture ===
-===d. Byssus   ===
-===e. Foot  ===
-===f. Mantel  ===
-===g. Operculum===
-===h. Mother of pearl===
-===i. Epidermis===
-===j. Ribs===
-===k. Teeth===
-===l. Concentric lines===
-===m. Canal===
-===n. Spines===
-===o. Whorls===
-===p. Lips===
-==6. Explain the development of a shell. How long do mollusks live?==
+== Shell formation ==
-==7. Give some facts about the life of a strombus pugilis (fighting conch) and explain why this shell is so named. ==
-==8. Explain the activities of the shipworm. ==
-{{:Adventist Youth Honors Answer Book/Nature/Shipworm}}
-==9. What accounts for the distribution of mollusks.==
+[[Nacre]] 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 [[animal shell|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.
-==10. Name two mollusks that have no shells. ==
-==11. Find answers for the following interesting questions: ==
+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.
-===a. How are bivalve and univalve animals fastened to their shells? ===
-===b. How is shell color controlled? ===
+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.
-===c. What mollusk has four gills? ===
-===d. From what sea animal was India ink formerly made? ===
+== The mantle cavity ==
-===e. What mollusk spins a silken thread? ===
+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).
-===f. What shells were used for money by ancient tribes? ===
-===g. What shell is considered sacred by the Tibetans? ===
+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.
-===h. Purple dye of ancient times came from the secretion of what mollusk? ===
-===i. What is the source of pearls? How are they formed? ===
+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.
-==12. Name six commercial uses for shells. ==
-==13. Do one of the following: ==
+== See also ==
-===a. Personally find and collect 40 species of shells representing the five classifications. List each shell as to the place and date it was found, common name, scientific name, and class. ===
+* [[Aperture (mollusc)|Aperture]]
-===b. Make a collection of 50 species of shells you have found, received, or purchased representing the five classifications. List each shell collected as follows: if personally found, give the information called for under letter "a" above; if received or purchased, give the name of the person from whom the shell was received, the habitat of the shell, the date of its acquisition, and its common name, scientific name, and class.===
+* [[Columella (mollusk)|Columella]]
-==References==
+* [[Operculum (gastropod)|Operculum]]
-[[Category:Adventist Youth Honors Answer Book|{{SUBPAGENAME}}]]
+[[Category:Animal anatomy]]
+[[Category:Molluscs]]
+[[Category:Cephalopod zootomy]]
+[[de:Pallium (Weichtiere)]]
+[[fr:Manteau (mollusque)]]
+[[it:Mantello (biologia)]]
+[[pl:Płaszcz (anatomia)]]
+[[pt:Manto (molusco)]]
+[[ru:Мантия моллюсков]]