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93 Cards in this Set
- Front
- Back
Reduced stress factors in marine environments |
-easy gas exchange -no problem with osmotic regulation -salinity, oxygen levels, temperature, and pH are relatively stable -Buoyancy -Obtaining food and sex easy |
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Types of motility |
-Planktonic -Sessile -Sedentary -Mobile |
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Systematics |
the study of the kinds and diversity of life on Earth, and of any and all relationships between them |
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Blastula |
hollow, fluid-filled ball of cells that develops by mitotic divisions of the zygote |
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Homology |
similarity due to descent from a common ancestor |
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Synapomorphy |
a homologous trait that identifies a group |
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Analogy |
unrelated species have a similar trait |
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Monophyletic group |
one that includes all the descendents of a single ancestor |
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Paraphyletic group |
a group that does not contain all the descendents of a single ancestor |
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Sister taxa |
derived from the same ancestor |
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Endoderm |
innermost layer of cells |
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Ectoderm |
outermost layer of cells |
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Mesoderm |
layer in between endoderm and ectoderm |
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Coelom |
internal body cavity |
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Acoelomate |
no coelom |
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Pseudocoelomate |
body cavity present, lined with endoderm on the inside and mesoderm on the outside |
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Coelomate |
body cavity present, and is lined with mesoderm on both the inside and the outside |
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Protostomes |
the mesodermal tissue splits internally to form a cavity |
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Deuterostomes |
the coelom forms through a series of infoldings |
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Blastopores form mouths in... |
protostomes |
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Blastopores form anuses in... |
deuterostomes |
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Cleavage pattern of protosomes |
spiral |
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Cleavage pattern of deuterostomes |
radial |
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Fission |
mitotic replication of chromosomes, followed by division of parent into two similar cells |
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Budding |
a small chunk of the parent breaks off, then grows into a new individual |
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Function of Archaeocytes in Porifera |
-Waste elimination -Food digestion -Reproduction |
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Categories of biological diversity |
-species richness -morphological diversity -behavioral and physiological diversity -ecological diversity |
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How marine environment minimizes physical and chemical stresses |
-wetness -little variation in pH, salinity, temperature, oxygen levels -buoyant |
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Causes of instability in freshwater environments |
-osmotic stresses -varying seasons -ephemeral
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Adaptations to ephemeral bodies of water |
-movement/dispersal -dormancy |
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Adaptations to seasonal fluctuations |
-dormancy |
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Problems with classification |
-overlapping categories -differences in juvenile and adult forms |
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Metazoan characteristics |
-multicellular -no cell walls -mobile |
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Evidence for seperate origins of multicellularity |
-embryological differences -cell to cell communication differences -regulatory and transcriptional gene differences |
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Ostia |
small pores water enters in sponges |
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3 types of sponge construction (simple to complex) |
-asconoid -syconoid -leuconoid |
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Class Calcarea |
spicules made of calcium carbonate |
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Class Demospongiae |
spicules made of silica and/or spongin |
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Class Hexactinellida |
spicules made of silica, with 6 rays |
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Class Homoscleromorpha |
silicaceaous spicules (if any); basal membrane underlying tissues; cilia |
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Characteristics of Cnidarians |
-radial symmetry -tissues no true organs -simple nervous system and cells that function like muscles |
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Gastrovascular cavity |
used for digestion and circulation |
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Mesoglea |
jellylike substance that fills the body between the GV cavity and the external surface |
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Cnidoblast |
a cell that secretes a stinging thread |
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Spongocoel |
the space inside a sponge |
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Choanoderm |
innermost layer in sponges |
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Pinacoderm |
outermost layer of the sponge |
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Spongin |
a fibrous protein that serves as a skeletal element in some sponges |
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Spicules |
pieces of calcium carbonate or silica that serve as skeletal elements in some sponges |
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Osculum |
the large opening through which water exits the sponge |
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Adaptations for regulating water and solutes |
-Reduced surface permeability -Excretory mechanisms
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Parabasala Euglenozoa Choanozoa |
Flagellates |
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-Ciliophora -Dinozoa -Apicomplexa -Amoebozoa |
Alveolate protozoans |
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The syncytial theory |
Metazoans started as a multinucleate protozoan something like paramecium |
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Arguments for syncytial theory |
Similarities between ciliophora and aceleomates such as (body shape, size, feeding habits) |
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Arguments against syncytial theory |
-Acelomates undergo complex embryonic development
-Flatworms may not be the most primitive metazoans |
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Colonial theory |
metazoans started as a flagellated protozoan that forms aggregations |
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Arguments for colonial theory |
-Many flagellated protozoans form loosely organized aggregations
-The body walls of the most primitive metazoan animals bear flagellated cells
-DNA data link the choanoflagellate protozoans to Porifera |
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Arguments against colonial theory |
aggregating protozoans are known |
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Growth factors in sponges |
-Wave action |
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Three types of symmetry |
-assymetry -bilateral -radial |
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Cephalization |
the concentration of nervous and sensory tissues and organs at the anterior end |
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Germ layers |
groups of cells that act together during the |
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Diploblastic |
two germ layers |
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Triploblastic |
three germ layers |
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Significance of coeloms |
-Gut is less affected by locomotor activity
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Infraciliature |
network of fibers connecting cilia |
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Ciliophora characteristics |
-cilia -infraciliature -two nuclei -cytostome |
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Characteristics of Dinozoa |
-Cellulose plates |
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Zooxanthellae |
photosynthetic species that provide nutrients to other animals (many corals, sponges, mollusks, worms, jellyfish, etc. |
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Characteristics of Amoebozoa |
-Lack cilia |
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Plasmodium |
aggregative phase of slime mold |
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Cladogram |
shows the homologous traits used to classify certain groups |
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Porifera |
sponges |
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Cnidaria |
-jellyfish -corals -sea anemones |
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Ctenophora |
-sea combs -comb jellies |
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Platyhelminthes |
-flatworms -tapeworms |
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Nematoda |
roundworms |
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Annelida |
-earthworms -leeches |
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Rotifera |
rotifers |
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Hemichordata |
Acorn worms |
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Chordata |
-tunicates -sea squirts -lancelets |
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Time of Cambrian explosion (in mya) |
540 mya |
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Oldest known metazoan fossils |
543 to 635 mya |
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Number of subdivisions of coelomic cavity in protosomes |
highly variable |
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Number of subdivisions of coelomic cavity in deuterostomes |
three pairs of cavities |
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Fate of earliest cells in protosomes |
determinate |
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Fate of earliest cells in deuterostomes |
indeterminate |
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Extrusomes |
organelles that can discharge content out of cells. |
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Alveolate phylums |
-Ciliophora -Dinozoa -Apicomplexa |
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Rhizaria phylums |
-Foraminifera -Radiozoa |
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Flagellated phylums |
-Parabasala -Euglenozoa -Choanozoa |
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Characteristics of Heliozoa |
-Pseudopodia thin, fixed in place -Have inner and outer body regions, but no membrane |