1. Chapter 22:
The Animal Kingdom

2. Characteristics of Animals: 1) Multicellular 2) Ingestive heterotrophs
Chapter 22: Animals
Characteristics of Animals:
1) Multicellular
2) Ingestive heterotrophs
3) Reproduce sexually (typically)
4) Lack cell walls
5) Are mobile (at some stage)
6) Respond to stimuli rapidly

3. Anatomical Features Separate Major Animal Groups:
Chapter 22: Animals
(Figure 22.3)
Anatomical Features Separate Major Animal Groups:
No Tissue
Tissue
Sponges lack true tissues
Tissue: Groups of cells that together
carry out a specific function

4. Simplest multi-cellular animal (colony of single-celled organisms)
Chapter 22: Animals
Sponges (5000 species):
Simplest multi-cellular animal (colony of single-celled organisms)
Found in aquatic environments (mostly marine)
Adults are sessile (i.e. attached)
Spicules: Skeletal projections
Reproduction:
Asexual = budding
Sexual = egg / sperm (drifting)

5. Organisms has mirror image halves
Chapter 22: Animals
(Figure 22.3)
Anatomical Features Separate Major Animal Groups:
Bilateral symmetry:
Organisms has mirror image halves
Cniderians lack bilateral symmetry
No BS
No Tissue BS
Tissue

6. Cnidarians (Hydra, Jellyfish, & Anemones - 9000 species):
Chapter 22: Animals
Cnidarians (Hydra, Jellyfish, & Anemones species):
Radial Symmetry: Any cut divides organism in equal halves
Found in aquatic environments (mostly marine)
Two body plans (tentacles = body extensions):
1) Polyp = Sessile form (e.g. hydra & anemones)
2) Medusa = Free-floating form (e.g. jellyfish)
Cnidocytes: Stinging cells (prey capture)
Reproduction:
Asexual = budding
Sexual = egg / sperm (drifting)

8. Fluid-filled cavity between gut and outer wall
Chapter 22: Animals
(Figure 22.3)
Anatomical Features Separate Major Animal Groups:
Body Cavity
Flatworms lack a body cavity
No BC BC
Body Cavity:
Fluid-filled cavity between gut and outer wall
No BS
No Tissue BS
Tissue

9. Flatworms (Platyhelminthes - 12,000 species):
Chapter 22: Animals
Flatworms (Platyhelminthes - 12,000 species):
Contain well-developed organs
Cephalization: Concentration of sense organs / nerves
in defined head region (i.e. brain)
Parasitic or free-living
Tapeworm (infect humans)

10. Chapter 22: Animals
Tapeworm
Life Cycle:
Cysts
(Figure 22.10)

11. Flatworms (Platyhelminthes - 12,000 species):
Chapter 22: Animals
Flatworms (Platyhelminthes - 12,000 species):
Contain well-developed organs
Cephalization: Concentration of sense organs / nerves
in defined head region (i.e. brain)
Parasitic or free-living
Tapeworm (infect humans)
Flukes (humans - Schistosoma)
Reproduction:
Sexual and asexual
Hermaphroditic: Contain both male
& female sex organs

12. Anatomical Features Separate Major Animal Groups:
Chapter 22: Animals
(Figure 22.3)
Anatomical Features Separate Major Animal Groups:
1) Endoderm
2) Mesoderm
3) Ectoderm No
Coelem
Coelem
Roundworms lack a true body cavity
No BC BC
True Body Cavity (Coelem):
Cavity completely lined with mesoderm
No BS
No Tissue BS
Tissue

13. Roundworms (Nematodes - 12,000 species):
Chapter 22: Animals
Roundworms (Nematodes - 12,000 species):
Pseudocoelem: Cavity not completely surrounded by
mesoderm
Inhabit nearly every region of earth
Parasitic and free-living (decomposers)
Reproduction = Sexual (separate sexes)
Trichinella
Body Cavity
Heartworm

14. Anatomical Features Separate Major Animal Groups:
Chapter 22: Animals
(Figure 22.3)
Anatomical Features Separate Major Animal Groups:
Deut.
Devel.
Proto.
Devel. No
Coelem
Coelem
Annelids, mollusks & arthropods
display unique developmental
steps (protostome development)
compared to echinoderms and
chordates (deuterostome development)
No BC BC
No BS
No Tissue BS
Tissue

15. Segmented Worms (Annelids - 9000 species):
Chapter 22: Animals
Segmented Worms (Annelids species):
Segmentation: Division of body into series of repeating
segments
Hydrostatic skeleton: Fluid-filled compartments provide
framework for muscles to work against
Earthworm
3 Groups:
1) Earthworms (land)
2) Polychaetes (water)
3) Leeches (moist environment)

16. Arthropods (Insects, arachnids, crustaceans - 1,000,000 species):
Chapter 22: Animals
Arthropods (Insects, arachnids, crustaceans - 1,000,000 species):
Dominant animals on earth (sheer volume)
Exoskeleton: External skeleton (composed of chitin)
Allowed for invasion of dry terrestrial habitat
Must be molted (= shed)
Segmentation present (head, abdomen, thorax)
3 major groups:
1) Insects (6 legs)
2) Arachnids (e.g. spiders, scorpians)
8 legs
3) Crustaceans (e.g. lobsters, crabs)

17. Mollusks (Snails, clams, squid - 50,000 species):
Chapter 22: Animals
Mollusks (Snails, clams, squid - 50,000 species):
Mantle: Extension of body wall that secretes shell
Reproduction: Sexual (separate species / hermaphrodites)
3 major groups:
1) Gastropods (snails / slugs)
Radula: “Tongue” used to scrape / grasp food
2) Bivalves (clams / scallops / mussels / oysters)
Possess two shells with flexible hinge
3) Cephalopods (octopuses / squid)
Have highly developed brain / sensory systems

18. Anatomical Features Separate Major Animal Groups:
Chapter 22: Animals
(Figure 22.3)
Anatomical Features Separate Major Animal Groups:
Deut.
Devel.
Proto.
Devel. No
Coelem
Coelem
Annelids, mollusks & arthropods
display unique developmental
steps (protostome development)
compared to echinoderms and
chordates (deuterostome development)
No BC BC
No BS
No Tissue BS
Tissue

19. Echinoderms (sea stars, sea urchins, sea cucumbers - 6500 species):
Chapter 22: Animals
Echinoderms (sea stars, sea urchins, sea cucumbers species):
Inhabit marine environments
Endoskeleton: Calcium carbonate plates under skin
Bilateral symmetry present in larvae (not always adults)
Relatively sessile
External sexual reproduction (can also regenerate)

20. Chordates (tunicate, lancelet, vertebrates - 40,000 species):
Chapter 22: Animals
Chordates (tunicate, lancelet, vertebrates - 40,000 species):
Four features possessed by all chordates:
1) Notochord: Stiff, flexible rod extending length of body
2) Dorsal, hollow nerve cord (= spinal cord)
3) Pharyngeal gill slits
4) Post-anal tail
Might only be observed
during development
Tunicate
Vertebrate
Lancelet

21. Chapter 22: Animals

22. Vertebrates (in chordate phylum):
Chapter 22: Animals
Vertebrates (in chordate phylum):
Notochord replaced by vertebral column (backbone)
Adaptations allowing for successful invasion of land:
1) Internal skeleton = larger size / greater mobility
2) Paired appendages = greater mobility
3) Increased brain size = greater perception / reaction
Groups:
Jaws
Cartilaginous Fish
(e.g. shark)
Jawless fish
(e.g. lamprey)
Bony fish
(e.g. coelacanth)
Bones
Most diverse
vertebrates

23. (e.g. frogs / salamanders)
Chapter 22: Animals
Escape from
water
Reptiles
(e.g. snakes / lizards
Amniotic Egg:
Egg doesn’t dry out
Vertebrate Groups, continued:
Amphibians
(e.g. frogs / salamanders)
Require water to breed
Mammary
Glands:
Milk production
Warm-blooded
Birds
(e.g. eagles)
(feathers)
Hair
Mammals
(e.g. apes)