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Presentation on theme: "Invertebrates."— Presentation transcript:

1 Invertebrates

2 Animal Characteristics
All organisms in this kingdom have these common characteristics: Multicellular Eukaryotes No cell wall- unlike fungi, plants, bacteria Heterotrophs– consumer not decomposer Have Specialized Cells- unlike protists

3 Needs of Animals Need: Sense and chase down food source
Adaptation: nervous / motor systems Need: Break up food and absorb nutrients Adaptation: digestive system Need: Deliver oxygen to all cells Adaptation: circulatory / respiratory systems

4 SYMMETRY Asymmetry – no symmetry
Radial symmetry - can cut in equal halves-more than one way Bilateral symmetry – allows for development of brain region in a central location (head)

5 Types of Symmetry Asymmetry

6 Asymmetry-Sponges Only

7 Radial Symmetry                                                                                      

8 Background: different types of body symmetry
*Usually simpler organisms *Usually more complicated organisms

9 Bilateral Symmetry They all have a head area with sense organs

10 Development of Organisms
Develop from a single cell, the zygote Mitosis forms new cell in a process called cleavage A hollow ball of cells are formed called a blastula Gastrulation is the folding in of the blastula to form two layers These two layers are the ectoderm and the endoderm

11 Development

12 Development Ectoderm develops into skin and nervous tissue
Endoderm develops into the lining of the digestive tract and organs associated with digestion In some animals the gastrula forms a mesoderm Mesoderm is the third layer and develops into muscles, circulatory, excretory, and respiratory systems

13 Development Protostome is an animal with a mouth that develops from the opening in the gastrula called the blastopore Deuterostome The anus develops from the opening in the gastrula

14 Body Plans Acoelom- do not have a body cavity, organs are imbedded in tissues Pseudocoelom -(partial) a body cavity partly lined with mesoderm Coelom- a body cavity that provides space for the development of internal organs (something for muscles to push against to move)

15 *Background: types of coelomes (body cavities)

16 Vertebrate vs Invertebrate
Vertebrate- has a backbone Invertebrate- has NO backbone

17 Exoskeleton Functions: Protection
Prevents water loss on land (waxy layer) Problems: Heavy Growth requires molting

18 Exoskeletons

19 Endoskeleton An internal skeleton that provides support inside the body Advantage: Organisms can grow larger with skeleton inside

20 Endoskeletons

21 Sponges Simplest Animals Asymmetry

22 Sponges Sessile - do not move Asymmetrical
No tissue (Only organized cells)

23 Sponges Oxygen and food come in through Diffusion
Filter Feeds as an adult

24 Sponge Reproduction Sexual – release sperm into water (external fertilization very common in aquatic animals) Hermaphroditism – sponges have sperm AND eggs to increase the odds of reproduction Offspring can swim to a new location Asexual fragmentation also possible

25 Cnidarians Sea Anemone (Polyp) Jellyfish (Medusa)

26 Cnidarians Evolution of Radial Symmetry
Extends tentacles equally in all directions (increase food uptake)

27 Cnidarian Characteristics
Basic digestive system Also basic nervous system (nerve net) O2 still enters by diffusion

28 Cnidarian Characteristics
Reproduces sexually and asexually Skeleton-none present, but dead coral remains are calcium carbonate

29 Body Plans of Cnidarians

30 Flatworms-Platyhelminthes
Planarian – not parasitic Tapeworm – parasitic

31 Flatworm Characteristics
No coelom – Why? Many are parasitic O2 and sugar are absorbed in host’s intestine Bilateral symmetry Reproduction-most are hermaphrodites

32 Tapeworms

33 Tapeworm Life Cycle

34 Uses Pharynx to obtain food
Flatworm or Planaria                                 See full-size image. Fresh Water Planaria Uses Pharynx to obtain food Salt Water Flatworms

35 Sheep Liver Fluke

36 Roundworms hookworm - parasitic

37 Roundworms Smooth, non-segmented body Pseudocoelom (moves more)
Can burrow through skin (walking around barefoot) Also enters through contaminated food

38 Roundworm Characteristics More Advanced
Bilateral symmetry Complete digestive system with mouth and anus Sexual reproduction Oxygen enters by diffusion

39 Hookworms, Pinworms, Tapeworms that were removed from a Brazilian boy treated on a Rockefeller foundation mission (early 1900’s) These parasites still affect people all over the globe.

40 Not a problem in U.S.

41 Why not? Food safety inspections Good sanitation
Medication widely available

42 Dirofilaria is a roundworm that causes heartworm disease in dogs.
Roundworms Dirofilaria is a roundworm that causes heartworm disease in dogs.

43 Ascaris: a parasitic roundworm
Other Roundworms

44 The roundworm is carried by mosquitoes in tropical Africa
Other Roundworms The roundworm is carried by mosquitoes in tropical Africa Elephantiasis results when a roundworm blocks the lymphatic system, causing severe swelling

45 Roundworms: Hookworms
                               Hookworms attached to the intestines

46 Segmented Worms Earthworm leech

47 Segmented Worm Characteristics
Bilateral symmetry Full Coelom (full range of motion, complex organs inside) Complete digestion system Most are hermaphrodites with sexual reproduction

48 Segmented Worm Characteristics
Gets O2 directly from moist skin, closed circulatory system with hearts to deliver Food – blood (leeches), or dirt (earthworms)

49 Earthworms Giant Earthworm Regular Earthworm

50 Earthworms Swallow dirt, filter out food
Loosen soil, helps to aerate soil for plants Also fertilizes plants with castings (poop)

51 Leeches Two chemicals in saliva to help it take blood from hosts
Anesthetic (blocks pain) Anti-coagulant (prevents blood clotting)

52 Mollusks Squid – no shell Snail – 1 shell Clam – 2 shells

53 These are all in the same group!?!
inside of a clam

54 Mollusk Characteristics
Bilateral symmetry Getting food – filter feeders (clams), grazers (snails), predators (slugs) Getting O2 – gills in aquatic mollusks, primitive lung in snails Open or closed circulatory system

55 Open vs. Closed Circulatory System
Blood in vessels Larger animals Open No blood vessels Blood surrounds body’s organs, delivers O2 Smaller animals

56 Mollusk Reproduction Hermaphrodites (both mollusks and segmented worms) Aquatic – release sperm and eggs into water Land – meet and swap sperm, fertilize eggs inside

57 Chambered Nautilus

58 Arthropods Four main classes within this HUGE phylum: Arachnids
Crustaceans Centipedes / millipedes Insects

59 Arachnids Chigger (flea) Black widow Brown recluse Scorpion Tick

60 Crustaceans Crab Lobster Barnacles

61 Many-footed ones Centipede Millipede

62 Insects Wasp Fire ants Grasshopper

63 Arthropod Characteristics
Most successful of all animal phyla Coelom Bilateral symmetry Segmented body Exoskeleton- NOT the same as mollusk shell

64 Arthropod Characteristics
Oxygen enters by spiracles and then into tracheal tubes in some arthropods. Book lungs in spiders. Reproduction- Internal fertilization (mating) in land arthropods and External fertilization in sea arthropods

65 Arthropod Characteristics
Open circulatory system Uses special jaws called mandibles Use Pheromones (chemical signals) for communication and mating

66 Arthropods: Complex Nervous System
Sophisticated sensory / motor control Compound eye of a fruit fly

67 Metamorphosis

68 Echinoderms sea urchin sea star sea cucumber

69 Echinoderm Characteristics
Bilateral symmetry in larvae Radial symmetry in adults (live on ocean floor) Coelom Endoskeleton Deuterostomes

70 Echinoderm Characteristics
Food – variety of diet (some eat clams, some eat algae, some filter feed) Water vascular system (water instead of blood to carry O2) Reproduction typical in water Regeneration possible in some

71 Chordates

72 All Chordates Have notochord – precursor to vertebral spinal column (semirigid, filled with fluid) Vertebrates replace this with a full spinal cord Some chordates are invertebrates still

73 Chordates Chordates have 3 subphylums Tunicates Lanceletes Vertebrates

74 Invertebrate Chordates
tunicate lancelet

75 Each of these is a Class in the Phylum Chordata

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