1. Introduction to animals Introduction to Animals – Ch. 32

3. The Nature of Animals Section 32.1

4. Classification: ● 95-98% of animals are invertebrates ● Without a backbone ● 2-5% of animals are vertebrates ● With a backbone

6. Animal Traits

7. Characteristics: All animals are: 1. Multicellular 2. Eukaryotic 3. Ingestive heterotrophs 4. Lacking in cell walls 5. Sexually reproductive 6. Able to move

8. 1. Multicellular Organization ● Cell specialization: the evolutionary adaptation of a cell for a particular function ● Tissue: group of similar cells that perform a common function ● Cell junctions: connections between cells that hold them together as a unit

9. Atom Molecule or compound Organelle CELL Levels of Organization Tissue Organ Organ system Organism Life begins

10. 2. Eukaryotic cells

11. 3. Ingestive Heterotrophy ● Getting complex organic compounds (carbon) from sources other than the sun ● Ingestion: taking in food usually in the form of an other organism ● Digestion: the body’s process of extracting organic molecules from food

12. Lions Feeding (Ingestion)

13. 4. Lack of cell walls

14. 5. Sexual Reproduction & Development ● Hermaphrodites: producing both eggs and sperm ● Examples: worms & sponges ● Most do NOT fertilize own eggs ● Why not? ● Zygote: diploid cell that results from the fusion of two haploid gametes ● Undergoes differentiation (cells becoming specialized to perform a specific function)

15. Mating and Mating Behaviors Beetles Mating Male Female Young Courtship

16. Leeches Exchange Sperm During Mating Mating leech

17. Parthenogenesis: ● Females of some animals produce eggs, but the eggs develop without being fertilized! ● New offspring will be all female ● Example animals: some fishes, several kinds of insects, and a few species of frogs and lizards

18. Parthenogenesis in the Komodo Dragon Video Video !

19. 6. Movement ● Sessile: attached & non-moving ● sponges ● Sedentary: move very little ● clam ● Motile: animals that can move ● humans ● Ability to move depends upon interaction between nervous tissue and muscle tissues ● Neurons: cells of nervous tissue

20. SESSILESEDENTARY MOTILE Sponge Chiton Cheetah

21. Origin of Animals: ● Animals came about in the water ● Evolved from colonial protists: ● Each organism had its own function (for the colony) much like each cell of the animal body has its own function (for the organism) Vide o

22. Body Structure: ● Symmetry is the arrangement of body parts around a central plane or axis ● Asymmetry occurs when the body can’t be divided into similar sections ● sponges

23. Radial symmetry ● when body parts are arranged around a central point ● like spokes on a wheel ● echinoderms ● Most animals are sessile (attached) or sedentary (move very little)

24. Bilateral symmetry ● when animals can be divided into equal halves along a single plane ● right and left sides that are mirror images of each other ● are usually motile ● Show cephalization ● concentration of sensory organs on the head (anterior) end

26. What type of symmetry is this?

27. Segmentation ● When an animal body is composed of a series of repeating similar units ● Example: earthworm (annelid) ● Segments may look different & have different functions ● Example: insects & crustaceans (arthropods)

28. Anatomical Terms: Dorsal: back surface of animal Ventral: underside of animal Anterior: front end of animal Posterior: rear end of animal Lateral: sides of animal Medial: along midline of animal Proximal: near to Distal: away from

29. Label the parts:

30. Comparison of Invertebrates & Vertebrates Section 32.2

31. Invertebrate groups Video !

32. Invertebrates ● Simplest animals ● Contain the greatest number of different species ● Most are aquatic ● Do NOT have a backbone ● Includes: ● sponges, cnidarians, flatworms, roundworms, annelids, mollusks, arthropods, & echinoderms

33. Sponges – Phylum Porifera Osculum of Sponge

34. Sea Anemone – Phylum Cnidaria Tentacles of Sea Anemone

35. More Phylum Cnidaria * Brain Coral Red jellyfish

36. Flatworms – Phylum Platyhelminthes Planarian Marine Flatworm

37. Roundworms - Phylum Nematoda Segmented Worms – Phylum Annelida Nematode Leech (segmented worm)

38. Phylum Mollusca (With and Without Shells) snailscallop nautilus nudibranch octopus

39. Phylum Arthropoda Dung beetle Horseshoe crab crayfish spider

40. Phylum Echinodermata Sea cucumber Sand dollar starfish Brittle star Sea fan (crinoid)

41. Symmetry ● Most are radial or bilateral ● Radial can receive stimuli and move in any direction (in water) ● Some are highly cephalized Bilateral but NOT an invertebrate Radia l Bilatera l

42. Support of the Body ● Various types of support: 1. Simple skeletons (sponges) 2. Fluid-filled body cavity (roundworms) 3. Exoskeleton (crayfish) ● Rigid outer covering for protection of soft tissue

43. 2 Types of Circulatory Systems: ● Open circulatory system: circulatory fluid is pumped by the heart through vessels into a body cavity ● Arthropods & most mollusks ● Closed circulatory system: circulatory fluid is restricted to vessels in a closed loop ● Squid (mollusk) V IDEO

44. Digestive & Excretory Systems ● Gut: a digestive tract running through the body ● Liquid wastes are excreted as ammonia ● highly toxic

45. Development ● Indirect Development: an intermediate larval stage occurs ● Flies ● Direct development: young animal appears similar to adult ● grasshoppers

46. Indirect Developme nt

47. Vertebrate Groups Video!

48. Fishes – Classes Myxini, Cephalaspidomorphi, Chondrichthyes, Actinopterygii, and Sarcopterygii lancelet ray anglerfish damselfish

49. Class Amphibia toad newt frog salamander

50. Class Reptilia Turtle Snake Alligator Lizard

51. Class Aves hummingbird ostrich lovebirds

52. Class Mammalia

53. Vertebrata ● More complex animals ● Most have a backbone made up of individual bones called vertebrae ● All species are in the Phylum Chordata ● From simplest to most complex groups: ● Fish ● Amphibians ● Reptiles ● Birds ● Mammals

54. Support of Body ● Vertebrates have endoskeletons ● Internal skeletons ● Supports more weight ● Grows as animal grows (no molting) ● Some vertebrates have skeletons of cartilage ● sharks, rays, and skates ● Other vertebrates have skeletons of bone and cartilage ● reptiles, birds, & mammals

55. Bone & Cartilage in Fetus

56. Segmentation ● Vertebrae: repeating bony units of the backbone ● Vertebrae & ribs are segmented

57. Body Covering ● Integument: outer covering of an animal ● Terrestrial animals are water-tight ● Why? ● Examples: feathers, hair, scales

58. Respiration & Circulation ● Respiration (breathing): ● Aquatic = gills ● Terrestrial = lungs ● Circulation: ● Closed circulation with multi-chambered heart ● Separates oxygen and deoxygenated blood ● Improves efficiency

59. Digestion & Excretion ● Digestion: ● Occurs in the gut (mouth → anus) ● Excretion: ● Kidneys: filters wastes from the blood while regulates water levels in the body

60. Nervous System ● Highly organized brains ● Each part has its own function

61. Fertilization & Development Section 32.3

62. Fertilization ● Definition: the union of the female and male reproductive gametes ● Results in a single diploid cell named the zygote I’m in!

63. Fertilization Steps: 1. Sperm’s membrane fuses with egg’s membrane 2. Electrical charge occurs to block entry of other sperm into egg 3. Sperm nucleus merges with egg nucleus forming zygote 4. DNA replication begins & cell division occurs V IDEO

64. Cleavage ● Definition: division of the zygote immediately following fertilization via mitosis ● Organism size does not increase even though number of cells does

65. V IDEO

66. Tissue Development ● Cleavage results in the formation of a hollow ball of cells called the blastula

67. Blastula The blastocoel is the center cavity of the blastula with 1 germ layer (blastoderm)

68. Tissue Development ● The blastula invaginates ● folds inward at one point ● Called Gastrulation ● The opening is called the blastopore ● The center is the primitive gut ● Archenteron blastopore Archenteron

69. Embryonic Development V IDEO

70. Tissues

71. Tissue Development: ● Germ layers: tissues found in the embryos of all animals except sponges ● Typically three layers in depth ● All body features arise from one of these layers ● Body cavities: fluid-filled space that forms between the digestive tract & outer wall of body during development ● Aids in movement of animal ● Reservoir for transport of materials

72. Germ Layers ● Form tissues, organs, & systems ● NOT present in sponges ● Ectoderm (outer) – forms skin, nerves, sense organs ● Endoderm (inner) – forms liver and lungs ● Mesoderm (middle) – forms muscles & other systems Animation

73. Body Cavities

74. Coelom = Body Cavity ● Internal body cavity fully lined with mesoderm ● Body organs suspended in this cavity

75. Types of body cavities: 1. Acoelomates: no body cavity ● solid bodies filled with cells ● sponges, cnidarians, & flatworms 2.Pseudocoelomates: “false body cavity” ● have a functional body cavity NOT fully lined with mesoderm ● Rotifer, roundworms 3.Coelomates: true coelom ● Mollusks, annelids, arthropods, chordates

76. Acoelomate ● no body cavity ● solid bodies filled with cells ● sponges, cnidarians, & flatworms

77. Pseudocoelomate ● “false body cavity” ● have a functional body cavity NOT fully lined with mesoderm ● Rotifer, roundworms

78. Coelmate: ● true coelom ● Mollusks, annelids, arthropods, chordates