• Radial Symmetry
• top and bottom, but no left and right
• 2 germ layers
• Cnidaria & Ctenophores ONLY

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• bilateral symmetry
• top/bottom, head/tail, left/right
• 3 germ layers

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• fluid filled area separating digestive tract from body wall
• not completely lined with mesoderm
• Nematoda

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• Fluid filled cavity completely lined w/ mesoderm
• Mesentaries connect layers and suspend organs
• 2 groups
• -Protostomes
• -Deuterostomes

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• echinoderms, chordates
• Embryo- radial and indeterminable
• Folds of archenteron form coelom (ENTEROCOELOUS)
• Blastopore becomes ANUS

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• Sponges (lack true tissue and organs)
• 2 layers of cells
• HERMAPHRODITES
• filter feeders (CHOANOCYTES-flagellated collar cells which create water current)

• Jellyfish, corals, hydras, anemones
• Radially symmetrical
• gastrovascular cavity and nerve net (basic brain)
• 2 layers of cells
• middle layer=mesoglia
• use tentacles w/ cnidocytes to capture prey

• Flatworms, Tapeworms, Flukes
• Flatworms-gastrovascular cavity and ACOELOMATES
• Centralized nerve nets, found in moist environments
• Tapeworms & flukes- parasites, need 2 hosts

• snails, slugs, oysters, octopuses, squids
• 3 main parts
  • Muscular foot
  • Mantle
  • visceral mass
• Complete digestive tract
• Open circulatory system
• Gas Exchange- Siphon system
• Nephridium excrete nitrogenous wastes
• Cephalopods- VERY SMART

• chitons
• ovalshaped marine animals encased in armor
  • eight dorsal plates

• Snails and Slugs
• single spiraled shell
• Torsion-mantle and anus above head

• clams, oysters
• 2 shells

• squid, octopus, cuttlefish, chambered nautiluses
• beaklike jaw
• tentacles of modified foot

• segmented worm
• earthworms, leeches, polychaetes
• gas exchange- through skin
• closed circulatory system
• excrete wastes through skin
• complete digestive system
• cerebrial ganglia
• dorsal nerve cord
• true coelom
  • hydrostatic skeleton
  • series of fused rings
  • circular & longitudinal muscles that contract against coelom

• Roundworms
• Pseudocoelomates
• moist places
• covered by cuticle (tough coat)

• Complete digestive system
• Gas exchange- trachea with spiracles to outside
• segmented ganglia
• anterior ganglia fused with dorsal brain
• Wastes- Malpighian tubules, empty to digestive tract
• regional segmentation
• jointed appendages for climbing, feeding, defense
• Cephalization- sensory structures at anterior end
• exoskeleton- protein & chitin
  • has to shed for animal to grow
  • thin and flexible at joints
  • provides protection, waterproofing
• Open Circulatory system
  • hemolymph goes all over the body instead of capillaries and arteries and such

• spider, scorpion, tick, mite
• feeding appendage- chelicerae

• Insects
• more species than all other forms of life combined
• several complex organ systems
• may undergo metamorphesis

• Crustaceans
• branched appendages
• special for feeding and locomotion

• large crustaceans
• lobster, crab, crayfish, shrimp

• thin, bumpy, spiny skin covers
• water vascular system
• radial
• deuterostomes
• hydraulic canals branching into tube feet for moving, feeding, gas exchange
• radial nerves
• eats from stomach pushing self out

• Bilateral Deuterostomes
• Notochord
  • flexible rod between digestive tube and nerve cord
  • skeletal support, often becomes spine
• Dorsal, hollow nerve cord
  • develops from plate of ectoderm
  • into CNS- brain and spinal cord
• Pharyngeal slits or clefts
  • gas exchange for aquatic vertebrates
  • develop into ears, head, neck of land vertebrates
• Muscular, post-anal tail
  • mostly lost during embryo
  • some remain for movement

• invertebrates
• closely related to vertebrates
• tunicates & lancelets (filter feeders)

• jawless fish
• hagfish
• skull and axial rod of cartilage
• secrete slime to ward away predators
• scavengers

• lampreys
• jawless aquatic vertebrate
• parasites of fish
• cartilaginous segments along spine and notochord

• sharks, rays, skates
• skeleton composed primarily of cartilage

• bony endoskeleton
• Fish- control buoyancy with swim bladder (an air sac)
• countercurrent of blood and water to maximize oxygen intake
• 2 chamber heart
• excrete salt from gills
• freshwater fish excrete a lot of dilute urine to maintain osmoregulation 

• 4 limbs and feet with digits

• frogs, salamanders, caeciliums
• moist skin that works with lungs for gas exchange
• means 2 lives
  • water life- beginning
  • life on land
• 3 chamber heart

• produce amniotic egg that protects embryo
• relatively impermeable skin
• rib cage that helps ventilate lungs

• brachiosaurs
• almost everything adapted for flight
• wings, feathers
• bones lightweight
• 4 chamber heart, 1 way flow of oxygen

• Amniotes
• produce milk through mammary glands
• larger brain that vertebrates of = size
• 4 chamber heart

• egg laying mammals
• platypus
• echidna

• longer period of pregnancy than marsupials
• finish development in uterus, joined to mother by placenta

• hands and feet for grasping
• large brain
• short jaw
• forward looking eyes on face, close (depth perception)
• well developed parental care & complex social behavior
• fully opposable thumb
• 3 groups
  • lemurs, lorises, pottos
  • tarsiers
  • anthropoids (monkeys and apes)