Exploring the Diverse Animal Kingdom: Characteristics and Evolution

1. Kingdom Animalia/Phylum Chordata

2. Kingdom Animalia: General Characteristics • All multicellular • All eukaryotic cells • All heterotrophic  ingest food • Carbohydrate reserve is glycogen • Lack cell walls

3. Have highly differentiated body cells organized into tissues/organs/organ systems for specialized functions such as: - Digestion • Internal transport • Gas exchange • Movement • Coordination • Excretion • Reproduction

4. Reproduction is usuallySEXUAL • Flagellated sperm fertilizes non-motile, larger eggs • DIPLOID stage dominates life cycle • Zygote undergoes series of mitotic divisions called CLEAVAGE, which produces a BLASTULA in most animals • GASTRULATION occurs after blastula is formed (embryonic forms of adult body tissues formed during it) • Development usually direct to maturation

6. Zygotic Cleavage

8. Found in SW, FW, and terrestrial habitats Each of these habitats present special problems/challenges to the animals living there • 11 – 35 Phyla total (Kingdom Animalia) Invertebrates = 95% Vertebrates = 5% >1 million species

9. Symmetry Types • Asymmetrical • No definite “head/tail” end, no left/right sides. • Amoeba proteus

10. Spherical • “Round” No L/R, H/T Yeast cell

11. Radial • Show polarity (H/T), but no L/R sides

12. Bilateral • Definite head/tail ends AND left/right sides. One side is usually a “mirror image” of the other side

13. Anatomical Directions • Dorsal: top • Ventral: bottom (belly) • Anterior: front (head) end • Posterior: back (tail) end • Lateral: side surfaces

16. Invertebrate Phyla • Porifera: Sponges. Asymmetrical. Most marine. No tissues/organs. Body wall consists of two layers of independent cells.

17. Cnideria • Jellyfish, corals, hydra, sea anemones. Radial symmetry. Marine or FW. Most gelatinous. Distinct tissues and a baglike body of two cell layers.

18. Ctenophora • Comb jellies. Radial symmetry. All marine, transparent, and gelatinous.

19. Platyhelminthes • Flatworms. Bilaterally symmetrical. Planaria, flukes, tapeworms.

20. Nematoda • Roundworms. Unsegmented, long & slender. ALL Parasites.

21. Rotifera • Free-living, aquatic.

22. Mollusca • Soft-bodied. Three part body (foot, visceral mass, mantle). Marine, FW, and terrestrial. Snails, slugs, clams, mussels, oysters, conches.

23. Annelida • Segmented worms. Earthworms, sandworms, bloodworms, leeches.

24. Arthropoda • Segmented bodies. Paired, jointed appendages. Exoskeleton. Insects, arachnids, centipedes, millipedes, crustaceans.

25. Echinodermata • All marine. Adults have pentaradial symmetry. Most have a water-vascular system and tube feet. Starfish, sea stars, feather stars, sea urchins, sand dollars, sea cucumbers.

26. Kingdom AnimaliaPhylum Chordata • Fish • Amphibians • Reptiles • Bird • Mammals

27. Phylum Chordata: General Characteristics • Notochord Embryonic structure. Stiff cartilagenous rod found on dorsal side of embryo. Serves as an internal skeleton (support). Replaced by vertebral column in most vertebrates early in life.

28. Notochord

29. Phylum-Chordata Subphylum-Cephalochordata Amphioxus, Lancelet notochord

31. Dorsal Nerve Cord Hollow. Surrounded by vertebral column. Anterior end = Brain. Rest = spinal cord Brain + Spinal Cord = Central Nervous System (CNS)

33. Gill slits or clefts Paired gill slits or pouches in throat region at some point in ALL vertebrate lives.

35. Vertebrate evolution was from water to land!

36. Ontogeny recapitulates phylogeny!

37. Chordate General Characteristics • Endoskeleton of bone or cartilage; jointed and flexible. Consists of: Vertebral Column (backbone): replaced notochord. Surrounds and protects dorsal nerve cord. Cranium encloses brain. Vertebral column + Cranium = Axial Skeleton

38. Axial Skeleton

39. Girdles • Groups of bones that connect limbs to axial skeleton • Pectoral Girdle: connect arms, forearms to axial skeleton

40. Pelvic Girdle: connect legs and forelegs to axial skeleton

41. Limbs: Usually paired. Legs, wings, flippers…. Girdles + Limbs = Appendicular Skeleton

43. 2 Major Body Regions = Head & Trunk Head contains brain & sense organs ….. Cephalization

44. Specialized Vertebrate Body Systems • Integumentary Outer body covering. Protection & temperature regulation. • Skeletal Bones, cartilage. Protection, support, anchor for muscle tissue.

45. Muscular Provides body movement. Forms organ walls. • Digestive Physically and chemically breaks food down into usable liquid nutrients • Excretory Processes, then rids body of various wastes (solid, liquid, gaseous)

46. Respiratory Gas exchange. Gets O2 to all cells, carries CO2 from them. • Circulatory “Internal transport.” Ventral heart. Arteries, Veins, Capillaries. Closed system. Blood contains RBCs with hemoglobin. • Immune Detects & destroys invaders of the body.

47. Endocrine Glands. Produce & secrete hormones that regulate body processes. • Nervous Sensory perception & voluntary movement • Reproductive Produces gametes though meiosis

48. Vertebrate Lines of Development • The movement to land caused many changes. What changes had to occur due to the new demands of life on land? Gills to lungs Stronger bones & muscles Reinforced joints Reproduction… why???

49. Vertebrate Behavior • Inborn Innate, Instinct - Reflexes - “Instinct” for Self/Species Preservation

50. Learned Behavior Not inherited. “Conditioned Response” “Intelligent behavior such as…… * Problem Solving * Judgement * Decision Making