1. PowerLecture: Chapter 25 Part I Chart Supplement Animal Evolution – The Invertebrates

2. Characteristics of Animals Characteristics of Animals  Multicelled Aerobic heterotrophic eukaryotes  Most reproduce sexually

3. Animal Origins  Originated during Precambrian (1.2 billion - 670 million years ago)

4. radial symmetry Fig. 25-5a, p.406 Radial Symmetry

5. dorsal anterior posterior ventral bilateral symmetry Fig. 25-5b, p.406 Bilateral Symmetry

6. Animal Tissues  Ectoderm  Endoderm  Mesoderm

7. The Gut - 2 types  Saclike gut One opening for taking in food and expelling waste One opening for taking in food and expelling waste  Complete digestive system 2 Openings; mouth and anus 2 Openings; mouth and anus

8. spongescnidariansechinodermsflatwormsannelidsmollusksroundwormsarthropodschordates multicelled body radial ancestry, two germ layers true tissues coelom lost coelom reduced pseudocoel coelom reduced molting PROTOSTOMES mouth from blastopore bilateral, coelomate ancestry, three germ layers DEUTEROSOMES anus from blastopore Fig. 25-7, p.407

9. Fig. 25-2a, p.404 Protostomes Deuterostomes

10. p.408

11. Choanoflagellates  Protozoans most closely related to animals  Resemble collar cells (stay tuned for more on this)

12. p.408

13. Sponges - Phylum Porifera  No symmetry, tissues or organs  Reproduce sexually

14. Sponge Structure central cavity water out water in flagellummicrovillinucleus glasslike structural elements amoeboid cell pore semifluid matrix flattened surface cells Fig. 25-10, p.409

15. Fig. 25-4a, p.405 flagellated collar cell Sponge collar Cell

16. Fig. 25-9a, p.408

17. Fig. 25-9b, p.408

18. Fig. 25-9c, p.408

19. p.408

20. Phylum Placozoa  One living species, Tricoplax adherens  2-layer body, 3 mm across Fig. 25-11, p.409

21. p.408

22. Cnidarian Diversity  Scyphozoans Jellyfish Jellyfish  Anthozoans Sea anemones Sea anemones Corals Corals  Hydrozoans

23. Fig. 25-14a1, p.411

24. Fig. 25-14a2, p.411

25. mesoglea- filled bell tentacles Fig. 25-13b, p.410

26. Two Main Body Plans outer epithelium (epidermis) mesoglea (matrix) inner epithelium (gastrodermis) Medusa Polyp Fig. 25-12, p.410

27. Phylum Cnidaria  Nematocysts barbed thread inside capsule capsule’s lid at free surface of epidermal cell trigger nematocyst Fig. 25-13, p.410

28. Fig. 25-45a, p.431

29. Fig. 25-14b, p.411

30. Obelia Life Cycle (Hydrozoan) reproductive polyp female medusa male medusa sperm zygote ovum planula polyp forming feeding polyp Fig. 25-15a, p.411

31. Protostomes Deuterostomes

32. Flatworms: Phylum Platyhelminthes  Acoelomates, bilateral, cephalized  Most hermaphroditic

33. Three Classes  Turbellarians (Turbellaria)  Flukes (Trematoda)  Tapeworms (Cestoda)

34. branching gut pharynx; protrudes onto food, then retracts into the body between feedings Planarian Organ Systems Digestive

35. rudimentary brain (pair of large ganglia in head) pair of nerve cords that have lateral branchings Planarian Organ Systems Neuro- sensory

36. ovary testis oviduct genital pore Planarian Organ Systems Reproductive

37. Fig. 25-16d, p.412 pair of highly branched tubules that adjust water and solute levels in body Planarian Organ Systems Excretory

38. Fig. 25-16e, p.412 opening of tubule at body surface flame cell

39. Fig. 25-16f, p.412 nucleus cilia fluid filters through membrane folds flame cell

40. Fig. 25-17, p.413

41. a Larvae, each with inverted scolex of future tapeworm, become encysted in intermediate host tissues (e.g., skeletal muscle) b A human, a definitive host, eats infected, undercooked beef which is mainly skeletal muscle proglottids c Each sexually mature proglottid has female and male organs. Ripe proglottids containing fertilized eggs leave host in feces, which may contaminate water and vegetation. d Inside each fertilized egg, an embryonic, larval form develops. Cattle may ingest embryonated eggs or ripe proglottids, and so become intermediate hosts scolex Fig. 25-18, p.413

42. proglottidsscolex Fig. 25-18e, p.413

43. Protostomes Deuterostomes

44. Rotifers  Bilateral  Cephalized  Crown of cilia at head  Complete gut

45. Fig. 25-22a, p.416

46. one of two ciliated lobes at head end cluster of nerve cells gastric gland (esophagus behind it) proto-nephridium cloaca (this type is a chamber for digestive and excretory wastes) gland that secretes cementing substance for “toe” mouth modified pharynx; internal jawlike elements, salivary glands stomach intestine anus one of two “toes” Fig. 25-22b, p.416

47. Two Coelomate Lineages Protostomes  Mollusks  Annelids  Arthropods Deuterostomes  Echinoderms  Chordates

48. Cleavage Patterns Protostome embryo (spiral cleavage) Deuterostome embryo (radial cleavage)

49. Protostomes Deuterostomes

50. Segmented, coelomate worms  Class Polychaeta  Class Oligochaeta  Class Hirudinea Annelids: Phylum Annelida

51. Polychaetes  Most marine  Bristles extend from parapods on each segment  Head end is specialized “jaws” toothlike structures pharynx (everted) antenna palp (food handling) tentacle eyes chemical- sensing pit parapod

52. Fig. 25-19a, p.414Polychaetes

53. Fig. 25-19b, p.414

54. Fig. 25-19c, p.414

55.  Predators and parasites  Less obvious segmentation Leeches - Class Hirudinea Leeches - Class Hirudinea

56. before feeding Fig. 25-20a, p.414

57. after feeding Fig. 25-20b, p.414

58. No parapodia, few bristles per segment Earthworm - An Oligochaete Nerve cord Dorsal blood vessel Nephridium Coelom Circular muscle Longitudinal muscle Seta (retracted) Fig. 25-21, p.415

59. Earthworm Nephridium bladderlike storage region of nephridium nephridium’s thin loop reabsorbs some solutes, relinquishes them to blood blood vessels body wall external pore (fluid containing wastes discharged here) funnel (coelomic fluid with waste enters here) Fig. 25-21, p.415

60. Earthworm Circulatory System Hearts Fig. 25-21, p.415

61. Earthworm Digestive System Pharynx Esophagus Crop Gizzard Coelomic chambers Mouth Fig. 25-21, p.415

62. Earthworm Nervous System Brain Nerve cord Fig. 25-21, p.415

63. head end Fig. 25-21g, p.415

64. on both sides of outwardly similar body segments are bristles used in locomotion Fig. 25-21h, p.415

65. Fig. 25-1, p.402 Old Genes, New Drugs

66. p.403 Old Genes, New Drugs