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20 Cards in this Set
- Front
- Back
characteristics of animals (4)
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multicellular
heterotrophs no cell walls extensive extracellular matrix gap junctions connect cells |
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what do animals usually have
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nerves
muscles able to move (@ some point) sexual reproduction |
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what did animals evolve from
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colonial flagellated protist
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what does monophyletic mean
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evolving from one common ancestor
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How many animal phyla are there
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about 35
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How can you classify using anatomical developmental features (5)
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- presence or absence of tissues
- type of body symmetry - number of embryonic cell layers - presence or absence of true body cavity - patterns of embryonic development .. different for many animals |
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types of tissues
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parazoa: no specialized tissues or organs
etmetazoa: more than 1 type of tissue and/or organs |
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types of symmetry
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radially: like plants with oral and aboral surfaces
bilaterally: with cephalization and dorsal/ ventral surface |
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number of embryonic germ cell layers
and names of layers |
2 embryonic cell layers- diploblastic: radial animals... endoderm: inner layer... ectoderm: outer layer
3 germ layers- triplpblastic: mesoderm- on inside if blastula endoderm/ ectoderm |
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what is the process of gastrulation and what does it form?
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zygote.. cleavage (cell division without growth).. 8 cell stage... cleavage...blastula (hollow ball of cells with blastocoel .. gastrulation .. starts invagination and eventually form hollow tube that runs through body ... forms muscles and most other organs
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body cavity types
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acoelomates: no body cavity
pseudocoelomates: body cavity but isnt lined with mesoderm coelomates: body cavity completely lined with mesoderm |
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how do coeloms develop
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- scizocoelous: solid mass of mesoderm splits to form coelom
- enterocoelous: mesoderm buds off from gut to form coelom |
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stages of embryonic development
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spiral cell cleavage creates protostomes- determinate cell cleavage- blastopore becomes mouth- goes through scizocoelous coelom development
radial cell cleavage creates deuterstomes- indeterminate cleavage- enterocoelous coelom development- blastopore becomes anus |
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what are other classifications of embyronic cell development
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presence or absence of:
exoskeleton, notochord/ vertebral column, metamerism (segmentation) |
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Draw cladogram!
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on paper
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Characteristics of parazoa: porifera
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Sponges, 8000 species (most marine), several cell types, no tissues, no consistent symmetry, reproduce sexually and asexually, free swimming larvae, sessile adults
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types of radiata
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Cnidaria: radial symmetry, 9000 species most marine, diploblastic, gastrovascular cavity for extracellular digestion, muscles(not mesodermal) and nerves (no brain)
Ctenophora: ~100 marine species, 8 rows of surface cilia for swimming, 2 long tentacles, 1st complete gut, separate mouth and anus, diploblastic |
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characteristics of most animals
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- triploblastic, usually complete gut, often have brain, 2 major groups: protostomia and deuterstomia, protosomes contain lophotrochozoans and ecdysozoans
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what do lophotrochozoas usually have and what are the 3 main groups
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lophophore (tentacles or crown)
or type of larvae called trochophore platyhelminthes, mollusca, annelida |
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characteristics of platyhelminthes
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~20,000 species, respire by diffusion, excretory system but no circulatory system, bilaterally symmetrical with head, acoelomate, light sensitive eyespot, nerve net with cerebral ganglia
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