Introduction to Animals Section 2 – Animal Kingdom Domain Bacteria Domain Archaea Domain Eukarya Common ancestor
Feb 09, 2016
Introduction to Animals
Section 2 – Animal Kingdom
DomainBacteria
DomainArchaea
DomainEukarya
Common ancestor
Introduction to Animals
Section 2 – Animal Kingdom
DomainBacteria
DomainArchaea
DomainEukarya
Common ancestor
Animal Characteristics • Heterotrophs
– must ingest others for nutrients• Multicellular
– complex bodies• No cell walls
– allows active movement• Sexual reproduction
– no alternation of generations– no haploid gametophyte
PoriferaCnidaria
Platyhelminthes
sponges jellyfish flatworms roundworms
NematodaMollusca Arthropoda Chordata
Annelida Echinoderm
mollusks
multicellularity
Ancestral Protist
tissues
bilateral symmetry
body cavity
segmentation
Animal Evolution
coelom
starfish vertebrates
endoskeleton
segmentedworms
insectsspiders
backbone
3 GERM layers ectoderm mesoderm endoderm
Body CavityHow much is the digestive tract separated from the rest of the body?
ectoderm
ectodermmesodermendoderm
ectodermmesoderm
endoderm
mesodermendoderm
acoelomate
pseudocoelomate
coelomate
coelom cavity
pseudocoel
Invertebrate: Porifera• Sponges
– Diploblastic (two germ layers)– no distinct tissues or organs
• do have specialized cells
– no symmetry– sessile (as adults)
food taken into each cell by endocytosis
Invertebrate: Cnidaria• Jellyfish, hydra, sea anemone, coral
– Diploblastic (two germ layers)– tissues, but no organs– radial symmetry– predators
• tentacles surround gut opening
• GASTROVASCULAR cavity• extracellular digestion
– release enzymes into gut cavity
Invertebrate: Platyhelminthes
ectoderm
mesodermendoderm
• Flatworms– Triploblastic (3 germ layers)– Acoelom– Fluke, tapeworm, Planaria– few parasitic– bilaterally symmetrical
• allows high level of specialization within parts of the body
• Most have one opening (GASTROVASCULAR CAVITY)
Invertebrate: Nematoda• Roundworms
– Triploblastic– Pseudocoelom– bilaterally symmetrical– have both mouth & anus
• well-developed digestive system– many are parasitic
• hookworm• pinworm
Invertebrate: Mollusca• Mollusks
– clams, snails, squid– bilaterally symmetrical (with exceptions)
– soft bodies, mostly protected by hard shells– true coelom
Invertebrate: Annelida• Segmented worms
– earthworms, leeches– segments are not specialized– bilaterally symmetrical– true coelom fan worm leech
Invertebrate: Arthropoda• Spiders, insects, crustaceans
– most successful animal phylum– bilaterally symmetrical– segmented
• allows jointed appendages– exoskeleton
• chitin + protein
Arthropod groups
insects6 legs, 3 body parts
crustaceansgills, 2 pairs antennaecrab, lobster, barnacles, shrimp
arachnids8 legs, 2 body partsspiders, ticks, scorpions
Invertebrate: Echinodermata• Starfish, sea urchins, sea cucumber
– Adults - radially symmetrical – spiny exoskeleton– Water vascular system
Invertebrate quick check…
• Which group includes snails, clams, and squid?• Which group is the sponges?• Which are the flatworms?
…segmented worms?…roundworms?
• Which group has jointed appendages & an exoskeleton?
• Which two groups are radially symmetrical?• Which group has no symmetry?
Invertebrates: Porifera, Cnidaria, Platyhelminthes, Nematoda, Annelida, Mollusca, Arthropoda, Echinodermata
• Vertebrates– fish, amphibians, reptiles, birds, mammals– internal bony skeleton
• backbone encasing spinal column
• skull-encased brain
postanaltail notochord
hollow dorsalnerve cord
pharyngealpouches
Chordata
becomes brain & spinal cord
becomes vertebrae
becomes gills or Eustachian tube
becomes tail or tailbone
Vertebrates: Fishsalmon, trout, sharks
• Characteristics – body structure
• bony OR cartilaginous skeleton• jaws & paired appendages (fins)• scales
– body function• gills for gas exchange• two-chambered heart;
single loop blood circulation• ectotherms
– reproduction• external fertilization• external development in
aquatic egg
gills
body
lung
buccalcavity
glottisclosed
Vertebrates: Amphibian• Characteristics
– body structure• legs (tetrapods)• moist skin
– body function• lungs (positive pressure) &
diffusion through skin for gas exchange• three-chambered heart/2 loops • ectotherms
– reproduction• external fertilization• external development in aquatic egg• metamorphosis (tadpole to adult)
frogssalamanders toads
Vertebrates: Reptilesdinosaurs, turtles lizards, snakesalligators, crocodile
embryoleatheryshell
chorion
allantoisyolk sac
amnion
• Characteristics – body structure
• dry skin, scales, armor– body function
• lungs for gas exchange• thoracic breathing; negative pressure• three-chambered heart/2 loops• ectotherms • excrete uric acid
– reproduction• internal fertilization• external development in amniotic egg
Vertebrates: Birds• Characteristics
– body structure• feathers & wings• thin, hollow bone;
flight skeleton– body function
• very efficient lungs & air sacs• four-chambered heart/2 loops• endotherms• excrete uric acid
– reproduction• internal fertilization• external development in amniotic egg
finches, hawk ostrich, turkey
trachea
anteriorair sacs
lung
posteriorair sacs
Vertebrates: Mammals• Characteristics
– body structure• hair• specialized teeth
– body function• lungs, diaphragm; negative pressure• four-chambered heart/2 loops• endotherms
– reproduction• internal fertilization• internal development in uterus
– nourishment through placenta• birth live young• mammary glands make milk
mice, ferret elephants, batswhales, humans
musclescontract
diaphragmcontracts
Vertebrates: Mammals• Sub-groups
– monotremes• egg-laying mammals• duckbilled platypus, echidna
– marsupials• pouched mammals• short-lived placenta• koala, kangaroo, opossum
– placental• true placenta• shrews, bats, whales, humans
Vertebrate quick check…• Which vertebrates lay eggs with shells?• Which vertebrates are covered with scales?• What adaptations do birds have for flying?• What kind of symmetry do all vertebrates have?• Which vertebrates are ectothermic and which are
endothermic• Why must amphibians live near water?• What reproductive adaptations made mammals very
successful?• What characteristics distinguish the 3 sub-groups of
mammals?