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152 Cards in this Set
- Front
- Back
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Clade |
a group of organisms containing the last common ancestor and all of its descendants |
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Metazoa |
a scientific word for "animals" |
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Protostome means "________________" |
mouth first |
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Deuterostome means "_______________" |
mouth second |
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2 sub-clades of the super-clade Protostomia |
Lophotrochozoa and Ecdysozoa |
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Lophotrochozoa |
lophophore feeding apparatus (ring of hollow tentacles) and/or a trochophore larvae, a type of motile larvae with a band of cilia around the middle |
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Ecdysozoa |
animals that molt, shed part of their body, at some point in their development |
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Edward Wilson |
"The Father of Biodiversity" professor emeritus at Harvard written many books |
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Geological time in the circular cladogram starts with what era in the middle? which is the outermost layer? |
inside - Hadean Era outisde - middle Cenozoic Era |
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describe the formation of the cladogram |
Time moves outward beginning with the Hadean Era in the innermost layer and Cenozoic on the outermost layer. The time of origin is where the branches begin. The ovals represent phyla. The width of the ovals is relative to the amount of species in that phyla. Some phyla are broken up into smaller phyla |
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Hadean Era |
4.6 billion years ago when the Earth formed. Ended around 3.8 billion years ago when the planet began to cool. Name in greek means "underworld." |
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Archaean Era |
3.8 billion years ago to 2.5 billion years ago. the first prokaryotes evolved (bacteria and archaea) these bacteria and archaea make up 2/3 major domains of life |
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Prokaryote |
organisms that lack a cell nucleus and any other membrane-bound organelles |
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Eukaryotes |
organisms that contain a cell nucleus and first appeared in the Proterozoic Era |
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Proterozoic Era |
first eukaryotes 2.5 billion - 543 million years ago "base of the Cambrian Period" Metazoans are first observed in the fossil record radiation of animals |
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Cambrian period |
600 million - 500 million years ago every phyla that is extant today evolved during this period
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Extant |
alive today |
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3 domains of life |
bacteria archaea eukaryotes |
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Opisthokonts |
the clade that contains fungi, choanoflagellates and the animals (in the eukaryote domain of life) |
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Animals are _____________, ______________, _____________, are capable of __________ at some point in development, and have regulatory genes called _____________ genes. |
multicellular, heterotrophic, lack a cell wall movement Hox genes |
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Hox genes |
only found in Metazoan clade -a group of genes that specify anterior-posterior axis and segment identity during early embryonic development -ONLY animals have Hox genes |
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animals are multicellular - meaning? |
differentiated cells for specialized functions but is not a defining feature of animals |
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Heterotroph |
ingest and digest their food but not a defining characteristic of animals |
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Capable of movement at some stage of development |
larval stage sponge moves but adult doesn't not a defining feature of an animal |
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no cell wall |
protists also lack a cell wall |
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What is biodiversity? |
-biodiversity is the totality of genetic diversity, species diversity, ecosystem diversity in a region |
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Species Diversity |
number of species in a region and their relative abundances |
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Species Richness |
number of species in a region (Earth has many millions of distinct biological species) |
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What percent of species richness do vertebrates make up? |
about 5% |
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What percent of species richness do invertebrates make up? |
about 95% |
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Pea-sized Pony |
-worlds smallest seahorse -named about 3 years ago -just over 1cm |
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Barbados Thread Snake |
under 10cm worlds smallest snake |
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Phylum Arthropoda make up what percentage of metazoan species? |
about 83% |
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How many Metazoan Phyla are there? |
34 |
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2 historic definitions of a phylum |
-as a group of organisms with a certain degree of morphological or developmental similarity (phenetic definition) -as group of organisms with a certain degree of relatedness (phylogentic definition) |
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Convergent Evolution |
describes the acquisition of the same biological trait in unrelated lineages -analogous structures or homoplasy |
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Divergent Evolution |
opposite of convergent, related secies evolve different traits -homologous structures |
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Stem Group Organisms |
lack one or more features that are present at the base of the crown group t which they are attached all members of the stem-group of a clade are extinct |
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Crown Group |
contains the last common ancestor of all extant members and all of the ancestor's descendants |
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Stem Group diagram |
-vertical line represents a clade of phylum -thin lines are stem members -thick lines are crown members -red dots are first appearance of crown member -red horizontal lines show stem members that evolved pre-Cambrian |
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Extremophiles |
organisms that live in harsh environments such as hot springs, salt lakes
first Archaea were extremophiles |
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Stromatolites |
are layered accretionary structures that form in shallow water formed by trapping and binding of sedimentary grains by biofilms of microorganisms, especially cyanobacteria |
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Rangeomorphs |
have branching "frond-like" elements. Each element is itself composed of many smaller elements |
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During the Cambrian Period, what was life like? |
all life was aquatic, most life was relatively small, many animals had unusual body layouts |
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Sanctacaris |
A large shrimp that grows to 9cm An arthropod A chelicerate |
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Chelicerate |
-Invaded earth more than 400 million years ago -arthropod group that includes spiders, scorpions, and horseshoe crabs. |
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Hallucegenia |
close relative of a rare modern animal known as onychophoran |
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Onychophoran |
-share certain characters with arthropods, but are lacking a hard exoskeleton or jointed legs -not a diverse group, less than 100 species extant today |
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Pikaia |
-thought to be a worm -now thought to be a chordate due to rod running along back |
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Opabinia |
-5 mushroom-shaped eyes, clawed proboscis, and unusual body -evolved alongside arthropods, chordates and echinoderms but it's lineage went extinct -might be closely related to arthropods (stem group) |
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4 broad habitat types |
Marine Freshwater Terrestrial Symbiotic or Parasitic |
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2 marine/freshwater habitats |
benthic pelagic |
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Benthic |
Bottom |
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Pelagic |
Top (water column) |
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2 Terrestrial habitats |
Xeric (dry) Moist |
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Parasitic habitat |
Negative effect on organism that is habitat e.g. Roundworm |
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Symbiotic Habitat |
Positive effect on both organisms e.g. Cleaner fish (Phyla Chordata) |
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2 Parasitic/Symbiotic Habitats |
Endo-parasites Ecto-parasites |
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In grid of 34 phyla, the colours mean what? |
Green: 1-100 species Blue: 100-1000 species Yellow: 1000-10000 species Orange: 10000-100000 species Red: 100000+ |
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What phyla have been sub-divided in the diagram? |
Arthropoda (crustacea, chelicerata, and uniramia) Chordata (urochordata and cephalachordata) |
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What habitats contain the most phyla? |
Aquatic (marine and freshwater) 29/34 phyla |
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Of the 5 phyla that aren't found in aquatic habitats, how many are not symbiotic/parasitic? |
1 (Onychophora) |
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How many phyla can be found in the marine habitat? How many can be found in the freshwater habitat? |
29, 14 |
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In the marine habitat, how many phyla can be found in the benthic habitat? pelagic?
In the freshwater habitat, how many phyla can be found in the benthic habitat? pelagic? |
29, 14
14, 6 |
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What phyla can be found in all three habitats? |
Nematoda, Arthropoda, and Chordata (3/34) |
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How many phyla have diversified to more than 100 000 species? |
2 (Arthropoda and Mollusca) |
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What are the 5 key transitions? |
Tissue Symmetry Body Cavity Development Segmentation |
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Cladogram |
a diagram which shows ancestral relations between organisms an represents the evolutionary tree of life |
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First branch of metazoan cladogram |
Phylum Placozoa from other metazoans |
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What is the second branch of the metazoan cladogram? |
Porifera from all other organisms. (Poriferans don't undergo gastrulation) |
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Gastrulation |
is a phase early in the development of most animal embryos, during which the morphology of the embryo is reorganized to form the germ layers: ectoderm and endoderm in diploblasts and ectoderm, endoderm and mesoderm in triploblasts. |
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What is the third split? |
Radiata (Cnidaria and Ctenophora, radial symmetry) and Bilateria (bilateral symmetry) |
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What id the evolutionary difference between protostomes and deuterostomes? |
blastopore becomes the mouth = protostome blastopore becomes the anus = deuterostome |
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Protostomes branch into how many super-clades? What are they called? |
2 the Lophotrochozoa (protostomes with a trochophore larvae or lophophore feeding apparatus) and the Ecdysozoa (molting animals) |
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Grades of Biological Organization |
Cellular Cell-Tissue Tissue Tissue-Organ Organ |
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Cellular Biological Organization |
see aggregation of cells that are functionally differentiated |
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Cell-Tissue Organization |
see a cellular organization where we have ensemble of cells that are functionally differentiated |
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Tissue Grade of Organization |
ensemble of cells that carry out a specific function |
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Tissue-Organ Grade of Organization |
aggregation of tissues first seen in Acoelomorpha |
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Organ Grade of Organization |
organs working together to perform a function highest grade of organization |
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Symmetry |
the balanced distribution of duplicate body parts or shapes |
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Bilateral Symmetry |
have a front and a back end, as well as an upside and downside |
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Assymmetry |
no axis of symmetry |
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Radial Symmetry |
topside (aboral) and downside (oral) but no front or back |
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Bi-radial Symmetry |
has both bilateral and radial axes of symmetry |
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Pentaradial Symmetry |
5-sided symmetry (starfish) |
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Acoelomate |
an animal that lacks a coelom |
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Pseudocoelomate |
2 body cavities formed but the pseudocoelum is not fully surrounded by a mesoderm so not a true cavity |
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Ceolomate Body Plan |
mesoderm splits into a true body cavity called the ceolom (developed in triploblasts but were lost in several lineages) |
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Triploblasts |
have a body made of 3 cellular layers, the exterior ectoderm and the interior endoderm and a middle mesoderm |
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What is another word for segmentation? |
metamerism |
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Segmentation |
is the repetition of a similar body segments along longitudinal axis of body |
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What is each segment called? |
metamere or somite |
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What is true metamerism? |
involves repetition of a structure with common function derived from both ectoderm and mesoderm |
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What is Serial Repetition? |
if the repetition only involves the ectoderm such as integument (skin) of some playhelminths such as the repeating nature of the proglottids in tapeworms (pink body sections) or the repeating nature of the integument of some of the nematodes. |
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How many times has metamerism independently evolved? In what? |
3 annelids, arthropods, and chordates |
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Porifera |
Sponges and Coral "pore-bearers" aquatic (mostly marine), benthic 9000 species named (about 100 in freshwater) no pelagic sponges sessile, live on substrate some are ectosymbionts or commensalists |
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Placozoa |
Marine only 1 species named |
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What are the 5 key transitions of Porifera? |
Tissue: cell-tissue Symmetry: assymmetrical Body Cavity: no body cavity Development: no germ layers (protostome) Segmentation: no |
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What are the 5 key transitions of Placozoa? |
Tissue: cell-tissue Symmetry: assymmetrical Body Cavity: no body cavity Development: no germ layers (protostome) Segmentation: no |
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Sponge Body is assembled of what? |
Gelatinous Matrix |
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Common characteristic of all sponges |
a body made up of a complex system of canals and pores which are open to the surrounding water |
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Hexactinellida |
glass sponge body made up of siliceous spicules with 6 rays |
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Calcarea |
strictly marine mostly in shallow tropical waters body made up of calcium carbonate 3 body grades: asconoid, synconoid and leuconoid |
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Demospongiae |
largest class of sponge secrete a form of collagen called spongin and secretes siliceous spicules "bath sponge" 90% of all sponges |
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Homoscleromorpha |
class of marine sponge made of 2 families 84 species in this class |
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Poriferans have a unique canal system called what? What does it do? |
Aquiferous system -system of canals and chambers connected to the surrounding environment by multiple pores -made of small incurrent pores (ostia) and 1 or more excurrent pores (oscula) and a spacious spongocoel. |
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The sponge body has 2 primary layers of cells. What are they called? |
Pinacoderm (outer layer) Choanoderm (inner layer) (between the two layers is a mesohyl) |
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Mesohyl |
the gelatinous matrix and is the connective tissue of the sponges - in it are found the ameoboid cells and the skeletal elements |
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Asconoids |
simplest body type; water enters through the ostia then goes to large internal chambers called the spongocoel (lined with cells called collar cells or choanocytes which are the main filter feeding apparatus of the sponge); asconoids are typically small - all under 10 cm and are tube shaped and attached to substrate; all are in the class Calcarea. |
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Synconoids |
thicker than asconoids; unlike the asconoid the layer where the spongocoel is found is folded into radial canals; the canals are lined with choanocytes; water enters radial canals through tiny openings called prosopyles; the water empties into spongocoel; all synconoids are in the class Calcarea |
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Leuconoids |
most complex; most efficient at pumping water; increased complexity of aquiferous system allows the sponge to not just pump more water but capture more food thus it is usually larger; diverse body type; have flagellated chambers; no spongocoel; demospongiae are all this type |
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The sperm and eggs of sponges are produced by what? |
choanocytes |
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4 types of Placozoan cells |
1) monociliated dorsal cells 2) ventral epithelia cells 3) ventral gland cells 4) syncytail fiber cells |
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Choanocytes |
make up the principle "pump" and "filter" of the system, driving water through the sponge, trapping and phagocytizing suspended bacteria and other particulate food |
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Archaeocytes |
are amoeboid cells that can transform into all other cell types (totipotent cell) |
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What are the 5 Key Transitions of Cnidaria? |
Tissue: tissue Symmetry: radial symmetry Body Cavity: no body cavity Development: diploblasts; protostrome Segmentation: no |
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What are the 5 Key Transitions of Ctenophora? |
Tissue: tissue Symmetry: bi-radial symmetry Body Cavity: no body cavity Development: diploblasts; protostrome Segmentation: no |
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What habitats are Cnidaria and Ctenophora found in? |
Solely aquatic (primarily marine); benthic or pelagic |
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What are the body plans of Cnidarians? |
benthic polyp form
pelagic medusae form |
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The polyp body form resembles a flower and stalk. Why? |
The stalk is a cylindrical column arising from the petal disk.
At the oral end is the manubrium: and elevation with the mouth at its summit situated in the centre of the oral disk |
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What shape is a medusa? |
an umbrella or bell |
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Cnidarians have an outer __________ and an inner ________________. |
epidermis; gastrodermis |
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What are the 5 classes of Cnidarians and the distinguishing features if each? What features do all Cnidarians share? |
All share: radial body form, cnidocytes, planula larvae, and a mouth surrounded by solid tentacles. Anthozoa (gut with septal filaments, siphonoglyph, anthozoan pharynx, hexaradial and octaradial symmetry), Staurozoa (creeping planula without cilia), Scyphozoa (rhopalium; polyp reduced or lost), Cubozoa (velarium), Hydrozoa (polyp lost, velum in medusae, medusae produced by lateral budding and enntocodon) |
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The external anatomy of the "classic" ctenophore is characterized by what? |
a sac-like body resembling a peeled grape |
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General function of nervous systems: |
to collect and process information about the surrounding environment, then to produce appropriate actions |
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General nervous system trend: |
a progression from diffuse nerve nets to highly centralized systems with differentiated sensory organs |
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The first nerves recognizable at the cellular level are found in the ______________. Nerves allow cells to transfer information from one cell to another. This is done in ___________ -- either through direct ______________ (electrical synapses) or via ______________ transmitters (chemical synapses). |
Cnidarians synapses transmission chemical |
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Cnidocyte |
endodermal interstitial cells
occur through the epidermis and are most abundant on the tentacles |
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Cnidocytes bear 2 important organelles. What are they? |
Nemacysts (a capsule with an inverted coiled tube and operculum)
Cnidocil (trigger for the ejection of the nematocyst) |
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Ctenophores have what instead of cnidocytes? |
collecytes (burst open when prey comes in contact with the tentacles, sticky threads released from each of the colloblasts will then capture the food) |
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Statocysts |
gravity-sensing structures
highly sensitive structures lined with sensory hairs, which transmit a signal when the hairs are bent. |
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What 3 features do Ctenophores share with Cnidaria? |
1) diploblast organization with extensive, mostly non-cellular middle layer (mesoglea) 2) possess only a mouth (no true anus; but some species in both phyla have anal pores) 3) gastrovascular cavity with radiating canals |
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5 major differences between Ctenophores and Cnidaria |
1) Asexual reproduction not well-developed 2) all are hermaphroditic but external cross fertilization is typical 3) use ctenes for movement rather than sheets of epitheliomuscular cells or myocytes 4) lack cnidocytes (instead have collecytes) 5) swim with their mouth forward |
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Platyhelminthes lives in what habitat? |
Moist Terrestrial, Marine, Freshwater |
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Acoelomorpha lives in what habitat? |
Marine (benthic and pelagic) |
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Which phyla (acoelomorpha or platyhelminthes) have many classes that are parasitic? |
Platyhelminthes (ecto- and endo-parasites) |
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What are the 5 key transitions of Acoelomorpha? |
Tissue: tissue-organ Symmetry: bilateral symmetry Body Cavity: acoelomate Development: triploblasts; protostome Segmentation: no |
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What are the 5 key transitions of Platyhelminthes? |
Tissue: tissue-organ Symmetry: bilateral symmetry Body Cavity: acoelomate Development: triploblasts; protostome Segmentation: no |
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What does A-P axis stand for? |
Anterior-Posterior Axis |
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Cephalization: |
is an evolutionary trend, whereby nervous tissue, over many generations, becomes concentrated toward one end of an organism forms a head region |
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Cephalization is intrinsically connected with a change in __________? |
symmetry |
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Why is the combination of cephalization and bilateral symmetry important in animals? |
it allows the sensory organs to face the direction of movement |
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What are the photoreceptors called in acoels? |
"ocelli" cup-shaped pigment cells that can sense the direction of light |
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Tubellaria |
one of the traditional sub-divisions of the phylum Platyheminthes, and include all of the sub-groups that are not exclusively parasitic
most forms reproduce sexually and with few exceptions |
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Planaria |
non-parasitic flatworms with ability to regenerate body parts |
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Neodermata contain what 3 parasitic groups? |
Cestoda, Trematoda, Monogenea |
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Cestodes are known as ___________? |
tapeworms |
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Trematoda are known as ____________? |
flukes |
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In what 3 ways do the 3 classes of Neodermata differ from free-living turbellaria? |
-lack sense organs -epidermis lacks cilia -have a weird syncytial epithelium with microvilli |
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Scolex |
The worm's head attaches to the intestine of the definitive host. |
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Proglottids |
successive segments that compose the body |
