Term
| In bigger metozoans what limits cell size? |
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Definition
| surface area to volume ratio issues |
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Term
| What is the major advantage to being multicellular? |
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Definition
| diversification of activities: different cells do different things |
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Term
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Definition
solitary or colonial aquatic eukaryotes that have a beating flagellum surrounded by a collar of microvilli that collect bacteria
they strongly resemble sponge feeding cells so people believe they might be a sister group to sponges |
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Term
| What grade of organization do porifera (sponges) have? |
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Definition
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Term
| What type of symmetry do sponges have? |
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Definition
Assymetrical
or superficial radial symmetry |
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Term
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Definition
form the rigid skeleton of a sponge
either calcareous or siliceous |
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Term
| Collagen fibrils in the intercellular matrix |
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Definition
| form the fibrous portion of the sponge |
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Term
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Definition
| have calcium carbonate spicules with one, three or four rays |
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Term
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Definition
| 6-rayed with siliceous spicules |
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Term
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Definition
siliceous spicules, spongin or both
95% of sponge species |
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Term
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Definition
| lack a skeleton, or have siliceous spciules without an axial filament |
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Term
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Definition
| a gelatinous matrix/connective tissue that sponge cells are arranged in |
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Term
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Definition
line the outer surface and form the pinacoderm
Can perform phagocytosis
mildy contractile, so they affect the shape of the sponge
Can be modified as myocytes/porocytes to form bands arounds pores to help regulate flow of water |
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Term
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Definition
move about the mesohyl
can specialize for reproduction, secreting skeletal elements, food transport and storage |
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Term
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Definition
blow the mesohyl, linning the inner chambers with one end embedded in the mesohyl
- collar of microvilli connected by microfillaments surrounds flagellum and forms a fine filtering device to strain food |
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
| In general, how do sponges eat? |
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Definition
| they collect particles from water pumped through internal canals which have dermal pores called ostia |
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Term
| How do choanocytes aid in feeding? |
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Definition
they collect food particles using flagella collar cells (a form of suspension feeding)
- the beating flagella keep the current flowing
-they trap and phagocytize passing food particles into food vacuoles, where digestion starts
- Partially digested food passes to specialized archaeocyte s(aka amoebocytes) for distribution through the body |
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Term
| How do pinacocytes aid in feeding? |
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Definition
| They may also phagocytize food particles at the sponge surface |
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Term
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Definition
Their spongocoels is flagellated
- simplest system --> small and tube shaped
- water enters via ostia, exits via osculum |
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Term
| What are the disadvantages to the asconoid canal system? |
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Definition
- limited surface area for food collection
- limited size and shape
- no advantage to being big, because if you were big you'd miss everything in the spogocoel |
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Term
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Definition
Flagellated Canals
- their body wall has choanocyte-lined radial canals that empty into the spongocoel
- water enters via PROSOPYLES and exits via APOPYLES into the spongocoel and out the osculum
folding in their surface areas means that most of the water passing through is accessible |
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Term
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Definition
Flagellated Chambers
- largest, most complex sponges
- Water enters incurrent canals via multiple ostia, and go to chambers with choanocytes
Water leaves via excurrent canals
Advantage: the high surface to volume ratio --> can filter all water present, meeting food demands |
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Term
| Asexual reproduction in sponges |
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Definition
Somatic embryogenesis : new sponges form from fragments
Bud formation - individuals break off and form new colonies
or by internal buds |
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Term
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Definition
an internal bud
created by a collection of archaeocytes that collect in teh meshyl and are then coated with spongin and spicules (they survive very extreme temperatures)
Cells escape the gemmule through a MICROPYLE and develop into new sponges |
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Term
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Definition
| the free swimming larva of sponges |
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