Introduction to animals

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

2. The Nature of Animals Section 32.1

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

4. 1,196,000 species

5. Characteristics: All animals are: • Multicellular • Eukaryotic • Ingestive heterotrophs • Lacking in cell walls • Sexually reproductive • Able to move

6. 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

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

8. 2. Ingestive Heterotrophy • Getting complex organic compounds 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

9. Lions Feeding (Ingestion)

10. 3. Lack of cell walls

11. 4. Sexual Reproduction & Development • Hermaphrodites: producing both eggs and sperm • Examples: worms & sponges • Do NOT fertilize own eggs • Zygote: diploid cell that results from the fusion of two haploid gametes • Undergoes differentiation (cells becoming specialized to perform a specific function)

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

13. Leeches Exchange Sperm During Mating leech Mating

14. 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

15. Parthenogenesis in the Komodo Dragon Video!

16. 5. 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

17. SESSILE SEDENTARY Chiton Sponge MOTILE Cheetah

18. 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)

19. 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

20. Radial symmetry • When body parts are arranged around a central point Ex) Echinoderms (sea star), Cnidarians (sea anemone) • Most animals are sessile (attached) or sedentary (move very little)

21. Bilateral symmetry • 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

24. What type of symmetry is this?

25. 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

26. Label the parts:anterior, posterior, dorsal, ventral, lateral, medial

27. Comparison of Invertebrates & Vertebrates Section 32.2

28. Invertebrate groups Video!

29. 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

30. Sponges – Phylum Porifera Osculum of Sponge

31. Sea Anemone – Phylum Cnidaria Tentacles of Sea Anemone

32. More Phylum Cnidaria Brain Coral Red jellyfish

33. Flatworms – Phylum Platyhelminthes Marine Flatworm Planarian

34. Roundworms - Phylum NematodaSegmented Worms – Phylum Annelida Nematode Leech (segmented worm)

35. Phylum Mollusca(With and Without Shells) snail scallop octopus nudibranch nautilus

36. Phylum Arthropoda spider crayfish Horseshoe crab Dung beetle

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

38. 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 Bilateral Radial

39. 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)

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

41. 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)

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

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

44. Ex) Indirect Development of Butterfly

45. Vertebrate Groups Video!

46. 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

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

48. salamander Class Amphibia toad frog newt

49. Class Reptilia Turtle Snake Lizard Alligator

50. Class Aves hummingbird ostrich lovebirds