Animal Characteristics
- Heterotrophs
- Must ingest others for nutrients
- Multicellular
- Complex bodies
- No cell walls
- Allows active movement
- Sexual reproduction
- No alteration of generation
- No haploid gametophyte
Body Cavity
- Space for organ system development
- Increase digestive and reproductive systems
- Increase gamete production
- Coelem
- Mesoderm and endoderm
- Allows complex structures to develop in digestive system
Invertebrate: Porifera
- Sponges
- No distinct tissues or organs
  - Do have specialized cells
- No symmetry
- Sessile
  - No adults
Invertebrate: Cnidaria
- Jellyfish, hydra, sea anemone, coral
- Tissues, but no organs
- Two cell layers
- Radial symmetry
- Predators
  - Tentacles surround gut opening
  - Extracellular digestion
  - Release enzymes into gut cavity
  - Absorption by cell lining gut
Invertebrate: Platyhelminthes
- Flatworms
- Tapeworm, planaria
- Mostly parasitic
- Bilaterally symmetrical
  - Have right and left, then have head end and posterior end
  - Cephalization

Development of brain

Concentration of sense organs in head
- Increase specialization in body plan
Invertebrate: Nematode
- Roundworms
- Bilaterally symmetrical
- Body cavity
  - Pseudocoelom
  - Simple body cavity
  - Digestive system
  - Tube running through length of body
- Many are parasitic
  - Hookworm
Invertebrate: Mollusca
- Mollusks
- Slugs, snails, clams, squid
- Bilaterally symmetrical with exceptions
- Soft bodies, mostly protected by hard shells
- True coelem
  - Increases complexity and specialization of internal organs
Invertebrate: Annelida
- Segmented worms
- Earthworms, leeches
- Segments
  - Increase mobility
  - Redundancy in body section
- Bilaterally symmetrical
- True coelem
Invertebrate: Arthropoda
- Spiders, insects, crustaceans
- Most successful animal phylum
- Bilaterally symmetrical
- Segmented
  - Specialized segments
  - Allows jointed appendages
- Exoskeleton
  - Chitin and protein
Arthropod Groups
- Arachnids
- 8 legs, 2 body parts
  - Spiders, ticks, scorpions
- Crustaceans
- Gills, 2 pairs antennae
  - Crab, lobster, barnacles, shrimp
- Insects
- 6 legs, 3 body parts
  - Butterfly, bees, ladybug
Invertebrate: Echinodermata
- Starfish, sea urchins, sea cucumber
- Radially symmetrical as adults
- Spiny exoskeleton
- Deuterostome
Chordata
- Vertebrates
- Fish, amphibians, reptiles, birds, mammals
- Internal bony skeleton
  - Backbone encasing spinal column
  - Skull-encased brain
- Deuterostome
Vertebrates: Fish
- Characteristics
- Body structure
  - Bony and cartilaginous skeleton
  - Jaws and paired appendages
  - Scales
- Body function
  - Gills for gas exchange
  - Two chambered heart
  - Single loop blood circulation
  - Ectotherms
- Reproduction
  - External fertilization
  - External development in aquatic egg
Vertebrates: Amphibian
- Characteristics
- Body structure
  - Legs
  - Moist skin
  - Gas exchange
- Body function
  - Lungs and diffusion through skin for gas exchange
  - Three chambered heart
  - Veins in lung back to heart
  - Ectotherms
- Reproductions
  - External fertilization
  - External development in aquatic egg
  - Metamorphosis
Vertebrates: Reptiles
- Characteristics
- Body structure
  - Dry skin, scales, armor
- Body function
  - Lungs for gas exchange
  - Thoracic breathing; negative pressure
  - Three chambered heart
  - Ectotherms
- Reproduction
  - Internal fertilization
  - External development in amniotic egg
Vertebrates: Birds (Aves)
- Characteristics
- Body structure
  - Feathers and wings
  - Thin, hollow bone flight skeleton
- Body function
  - Very efficient lungs and air sacs
  - Four chambered heart
  - Endotherms
- Reproduction
  - Internal fertilization
  - External development in amniotic egg
Vertebrates: Mammals
- Characteristics
- Body structure
  - Hair
  - Specialized teeth
- Body functions
  - Lungs, diaphragm
  - Four chambered heart
  - Endotherms
- Reproductions
  - Internal fertilization
  - Internal development in uterus
  - Nourishment through placenta
  - Birth live young
  - Mammary glands make milk
- Subgroups
- Monotremes
  - Egg-layaing mammals
  - Lack of placenta and true nipples
  - Duck-billed platypus, echidna
- Marsupials
  - Pouched mammals
  - Offspring feed from nipples in pouch
  - Short-lived placenta
  - Koala, kangaroo, opossum
- Placental
  - True placenta
  - Nutrient and waste filter
  - Shrews, bats, whales, humans