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Unique traits of animals
- multicellular
- ingest their food
- move under their own power at some point during their life cycle
- extracellular matrix
- muscle tissue
- nervous system
- no alternation of generation
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heterotroph
obtain carbon compounds from other organisms
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primary producer
produce their own carbon from inorganic elements
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consumer
eat producer and other organisms
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body plan and the 4 main features
animal's architecture
- - number of tissue layers around embryos
- - type of body symmetry and degree of cephalization (nervous system focus in one point - head)
- - fluid-filled body cavity?
- - development of embryo
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tissue
cells in integrated structural/functional units
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epithelium
tightly joined cells that covers the surface
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diploblasts
two types of tissue layers in embryo
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triploblasts
embryos with three types of tissue layers
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germ layers
organization of tissue layers
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ectoderm
- outer layer
- forms the skin and nervous system
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endoderm
- inner layer
- lining of digestive tract
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mesoderm
- only in triploblasts
- gelatinous material between endoderm and ectoderm
- forms circulatory system, muscle, bones, organs
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In diploblasts, the endoderm and ectoderm form...
muscle (ecto) and reproductive tissue (endo)
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Cnidaria
- diploblast
- (jellyfish, corals, anemone, sea pens)
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radial symmetry
- at least 2 planes of symmetry
- radiates outward like spokes on a wheel
- most live in the water or are attached to a substrate
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bilateral symmetry
- long, narrow body
- allowed for cephalization (feeding/sensory focused on one end, locomotion on the other end)
- better for catching food if movement is directed by head region and powered by posterior region -> rapid, directed movement and hunting
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coelom
enclosed, fluid-filled cavity
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coelemates
triploblasts with coelom
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pseudocoelom
coelom that forms within the mesoderm itself
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hydrostatic skeleton
skeletons comprised of enclosed, fluid-filled chambers - the water cannot be compressed
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Bilateria
group of organisms that have been bilaterally symmetric at some point in their life cycle
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Protostomes
most animal speicies
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Deuterostomes
chordates and echinoderms
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cleavage
rapid series of mitotic divisions that occurs in absence of growth
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spiral cleavage
helical arrangement of cells due to arrangement of mitotic spindles (mostly in protostomes)
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radial cleavage
cells stack on top of each other after cleavage (mostly in deuterostomes)
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gastrulation
- cell mvts that forms the 3 tissue layers in embryo
- cell moves into center of embryo, causing a pore to open
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gastrulation in protostomes
forms the mouth first and the anus later
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gastrulation in deuterostomes
forms the anus first and then the mouth
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coelem formation in protostomes
cavities form in mesoderm to form coelem
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coelem formation in deuterostomes
layers of mesodermal cells on the side of the gut that pinches off to form the coelem
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tube within a tube
- inner tube = animals' gut
- outer tube = body wall
- mesoderm in between forms the organs and muscles
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closest living relatives to animals
choanoflagellates
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most basal animal phylum
porifera (sponges)
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sessile
adults live permanently attached to a substrate
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choanocytes
sponge feeding cells (food is trapped and ingested)
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most ancient group
bilaterally symmetric triploblast (Acoelomorpha)
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ecysozoa
- one branch of protostomes
- arhtropods and nematodes
- grow by shedding their external skeleton and growing their body
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lophotrochozoa
- other branch of protostomes
- molluscs and annelids
- grow by extending the size of their skeletons
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segmentation
when the body is divided into repeated structures
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vertebrate
- monophyletic lineage
- defined by presence of a skull and backbone
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What normally causes diversification of species within a lineage?
innovative methods for feeding and eating
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suspension feeding (filter feeder)
filter out/concentrate particles suspended in air/water
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deposit feeder
- digest organic matter in soil as they burrow through
- simple mouthparts, wormlike body structure
- variety of lineages
- ex. sea cucumbers
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fluid feeder
- suck/mop up liquids (nectar, plant sap, blood, fruit juice)
- many lineages
- mouthparts that can pierce seeds
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mass feeder
- take chunks of food into their mouths
- mouths depend on type of food ingested
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radula
feeding structure like a rasp/file to scrape off material on plant/algae
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endoparasite
- live inside their hosts and absorb nutrients from host
- wormlike bodies
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ectoparasites
- live outside host
- mouthparts that pierce the skin and absorb nutrients
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What is the function of locomotion?
- find food
- find mates
- escaping from predators
- limbs are homologous (inherited from same ancestor)
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distal-less
gene that helps form limbs during development
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internal fertilization
sperm-transfer organ is placed into body of female
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external fertilization
- common in aquatic species
- females lay eggs into open water/males shed sperm on or near eggs
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viviparous
- "live bearing" - nourish embryos inside body
- give birth to live young
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ovoviviparous
keep eggs inside the body, but the egg is nourished by the yolk and not the mother
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holometabolous
- form of metamorphosis
- juvenile from (larvae) is different from adult form
- creates a "pupa" in between juvenile and adult form
- more popular because the juveniles and adults are feeding on different things = less competition
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hemimetabolous
juvenile form is called a nymph (look like mini adults)
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complete metamorphosis
cnidarians - polyp (sessile form) alternates with a medusa (free-floating)
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colony
group of identical individuals that are physically attached
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