2. AP Biology D.N.A Objective: SWBAT explain the origin and diversity of animals  What do you believe are the characteristics that separate animals from the other groups of living things?

3. AP Biology HOMEWORK  Cladogram practice and discussion question posted on wikispace  Due Friday by 11:59 pm

4. AP Biology 2007-2008 Domain Bacteria Domain Archaea Domain Eukarya Common ancestor Kingdom: Animals Domain Eukarya

5. AP Biology Animal Characteristics  Heterotrophs  must ingest others for nutrients  Multicellular  complex bodies  No cell walls  allows active movement  Sexual reproduction  Variety of organisms

6. AP Biology 2004- 2005 Early embryonic stages  Zygote (fertilization of egg and sperm)  solid ball stage  Blastula  hollow fluid-filled ball stage  by time human embryo reaches uterus  Gastrula  development of primitive digestive tract (gut) & tissue layers

7. AP Biology Gastrulation  zygote  blastula  gastrula How you looked as a gastrula…

8. AP Biology “BODY PLAN”  Biologists categorize the diversity of animals by body structure  Helped to infer the phylogenetic relationship between animal groups

9. AP Biology SYMMETRY  Some animals have radial symmetry  Like in a flower pot Figure 32.7a Radial symmetry. The parts of a radial animal, such as a sea anemone (phylum Cnidaria), radiate from the center. Any imaginary slice through the central axis divides the animal into mirror images. (a)

10. AP Biology  Some animals exhibit bilateral symmetry  Or two-sided symmetry Figure 32.7b Bilateral symmetry. A bilateral animal, such as a lobster (phylum Arthropoda), has a left side and a right side. Only one imaginary cut divides the animal into mirror-image halves. (b)

11. AP Biology  Bilaterally symmetrical animals have  A dorsal (top) side and a ventral (bottom) side  A right and left side  Anterior (head) and posterior (tail) ends  Cephalization - the development of a head

12. AP Biology ORGANIZATION OF TISSUE  Animal body plans  Also vary according to the organization of the animal’s tissues  Tissues  Are collections of specialized cells isolated from other tissues by membranous layers

13. AP Biology Gastrulation (creation of gastrula (early multicellular embryo)  zygote  blastula  gastrula  rearranges the blastula to form 3-layered embryo with a primitive gut

14. AP Biology Body Cavities  In triploblastic (3 tissue layers) animals  A body cavity may be present or absent  Body Cavity - Fluid-filled space between the digestive tract and body wall  cushions the internal organs  enables growth and movement

15. AP Biology Primary tissue or “germ” layers  ectoderm  external surfaces: skin  epidermis (skin); nails, hair & glands; tooth enamel; eye lens; epithelial lining of nose, mouth & rectum; nervous system  endoderm  internal lining  epithelial lining of digestive tract & respiratory systems; reproductive system & urinary tract; digestive organs  mesoderm  middle tissues: muscle, blood & bone  notochord; skeletal, muscular, circulatory, lymphatic, excretory & reproductive systems; lining of body cavity

16. AP Biology  A true body cavity  Is called a coelom and is derived from mesoderm Figure 32.8a Coelom Body covering (from ectoderm) Digestive tract (from endoderm) Tissue layer lining coelom and suspending internal organs (from mesoderm) Coelomate. Coelomates such as annelids have a true coelom, a body cavity completely lined by tissue derived from mesoderm. (a)

17. AP Biology  A pseudocoelom (false body cavity)  Is a body cavity partially lined by tissue from the mesoderm Figure 32.8b Pseudocoelom Muscle layer (from mesoderm) Body covering (from ectoderm) Digestive tract (from ectoderm) Pseudocoelomate. Pseudocoelomates such as nematodes have a body cavity only partially lined by tissue derived from mesoderm. (b)

18. AP Biology Acoelomates  Organisms without body cavities Figure 32.8c Body covering (from ectoderm) Tissue- filled region (from mesoderm) Digestive tract (from endoderm) Acoelomate. Acoelomates such as flatworms lack a body cavity between the digestive tract and outer body wall. (c)

19. AP Biology Protostome and Deuterostome Development  Based on certain features seen in early development  Many animals can be categorized as having one of two developmental modes: protostome development or deuterostome development

20. AP Biology 2004- 2005 Basic body plan  Protostomes (stoma – mouth)  “1 st mouth”  blastopore = mouth  Invertebrates  Deuterostomes  “2 nd mouth”  blastopore = anus  echinoderms & vertebrates

21. AP Biology Mini Poster Project  Each group will focus on a specific animal group  Name  Picture/Examples  Body plan  Symmetry?  Coelom  Cephalization  Anything special about the animal group that distinguishes it from the rest

22. AP Biology Invertebrate: Porifera  Sponges  no distinct tissues or organs  do have specialized cells  no symmetry  sessile (as adults) food taken into each cell by endocytosis

23. AP Biology 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 cells lining gut medusapolyp

24. AP Biology hydra stinging cell with nematocyst trigger discharged nematocyst undischarged nematocyst tentacles mouth sensory cell stinging cell Stinging cells of Cnidarians

25. AP Biology Invertebrate: Platyhelminthes ectoderm mesoderm endoderm  Flatworms  tapeworm, planaria  mostly parasitic  bilaterally symmetrical  have right & left & then have head (anterior) end & posterior end  cephalization = development of brain  concentration of sense organs in head  increase specialization in body plan Animals now face the world head on! acoelomate

26. AP Biology Invertebrate: Nematoda  Roundworms  bilaterally symmetrical  body cavity  pseudocoelom = simple body cavity  digestive system  tube running through length of body (mouth to anus)  many are parasitic  hookworm C. elegans

27. AP Biology Invertebrate: Mollusca  Mollusks  slugs, snails, clams, squid  bilaterally symmetrical (with exceptions)  soft bodies, mostly protected by hard shells  true coelem  increases complexity & specialization of internal organs

28. AP Biology Invertebrate: Annelida  Segmented worms  earthworms, leeches  segments  increase mobility  redundancy in body sections  bilaterally symmetrical  true coelem fan wormleech

29. AP Biology Invertebrate: Arthropoda  Spiders, insects, crustaceans  most successful animal phylum  bilaterally symmetrical  segmented  specialized segments  allows jointed appendages  exoskeleton  chitin + protein

30. AP Biology Arthropod groups insects 6 legs, 3 body parts crustaceans gills, 2 pairs antennae crab, lobster, barnacles, shrimp arachnids 8 legs, 2 body parts spiders, ticks, scorpions

31. AP Biology Invertebrate: Echinodermata  Starfish, sea urchins, sea cucumber  radially symmetrical as adults  spiny endoskeleton  deuterostome loss of bilateral symmetry?

32. AP Biology 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 have radial symmetry?  What is the adaptive advantage of bilateral symmetry?  Which group has no symmetry? Invertebrates: Porifera, Cnidaria, Platyhelminthes, Nematoda, Annelida, Mollusca, Arthropoda, Echinodermata

33. AP Biology  Vertebrates  fish, amphibians, reptiles, birds, mammals  internal bony skeleton  backbone encasing spinal column  skull-encased brain  deuterostome Chordata postanal tail notochord hollow dorsal nerve cord pharyngeal pouches becomes brain & spinal cord becomes vertebrae becomes gills or Eustachian tube becomes tail or tailbone

34. AP Biology Vertebrates: Fish salmon, trout, sharks 450 mya  Characteristics  body structure  bony & 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

35. AP Biology Transition to Land Evolution of tetrapods Tibia Femur Fibula Humerus Shoulder Radius Ulna Tibia Femur Pelvis Fibula Lobe-finned fish Humerus Shoulder Radius Ulna Pelvis Early amphibian

36. AP Biology lung buccal cavity glottis closed Vertebrates: Amphibian  Characteristics  body structure  legs (tetrapods)  moist skin  body function  lungs (positive pressure) & diffusion through skin for gas exchange  three-chambered heart; veins from lungs back to heart  ectotherms  reproduction  external fertilization  external development in aquatic egg  metamorphosis (tadpole to adult) frogs salamanders toads 350 mya

37. AP Biology 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 250 mya dinosaurs, turtles lizards, snakes alligators, crocodile embryo leathery shell chorion allantois yolk sac amnion

38. AP Biology Vertebrates: Birds (Aves)  Characteristics  body structure  feathers & wings  thin, hollow bone; flight skeleton  body function  very efficient lungs & air sacs  four-chambered heart  endotherms  reproduction  internal fertilization  external development in amniotic egg 150 mya finches, hawk ostrich, turkey trachea anterior air sacs lung posterior air sacs

39. AP Biology Vertebrates: Mammals 220 mya / 65 mya mice, ferret elephants, bats whales, humans muscles contract diaphragm contracts  Characteristics  body structure  hair  specialized teeth  body function  lungs, diaphragm; negative pressure  four-chambered heart  endotherms  reproduction  internal fertilization  internal development in uterus  nourishment through placenta  birth live young  mammary glands make milk

40. AP Biology Vertebrates: Mammals  Sub-groups  monotremes  egg-laying mammals  lack placenta & true nipples  duckbilled platypus, echidna  marsupials  pouched mammals  offspring feed from nipples in pouch  short-lived placenta  koala, kangaroo, opossum  placental  true placenta  nutrient & waste filter  shrews, bats, whales, humans

41. AP Biology 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?

42. AP Biology 2007-2008 That’s the buzz! Any Questions?

43. AP Biology Porifera Cnidaria Platyhelminthes spongesjellyfishflatworms roundworms Nematoda MolluscaArthropodaChordata AnnelidaEchinodermata mollusks multicellularity Ancestral Protist tissues bilateral symmetry body cavity segmentation Animal Evolution coelom starfishvertebrates endoskeleton segmented worms insects spiders backbone specialization &  body complexity specialized structure & function, muscle & nerve tissue distinct body plan; cephalization  body complexity  digestive & repro sys  digestive sys  body size redundancy, specialization,  mobility  body & brain size,  mobility radial bilateral

44. AP Biology Body Cavity ectoderm mesoderm endoderm ectoderm mesoderm endoderm mesoderm endoderm acoelomate pseudocoelomate coelomate coelom cavity pseudocoel  Space for organ system development  increase digestive & reproductive systems  increase food capacity & digestion  increase gamete production  Coelem  mesoderm & endoderm interact during development  allows complex structures to develop in digestive system  ex. Stomach  CLICK FOR VIDEO CLICK FOR VIDEO protostome vs. deuterostome