Kingdom Animalia

1. Kingdom Animalia The study of animals is called Zoology

2. The Animals have 6 major Characteristics 1. Animals are multicellular ……………….. Except for sponges, animal cells are arranged into tissues (a tissue is a group of cells alike in structure and function… such as muscle tissue or brain tissue). Tissues are necessary to produce organs and organ systems.

3. 2. Animals are heterotrophs Heterotrophs can only consume their foods….. they are not capable of making their own foods.

4. 3. Animals are diploid The dominant generation in the life cycle is the diploid generation. Their gametes are heterogametes (different sizes); eggs are larger than sperm. Gametes are produced by meiosis. A typical animal life cycle is shown below.

5. Human Life Cycle

6. 4. Animals are motile Heterotrophy often requires motility (the ability to move) to capture prey. Animals have motility during at least some part of their life cycle.

7. 5. Animals have a period of embryonic development During embryonic development, cells become specialized and form two or three layers of tissues. Tissues are groups of similar cells. Cell Specialization allows cells to perform more efficiently than requiring individual cells to perform many functions. Cell Specialization allows the Division of Labor.

8. 6. Animal cells lack cell walls Therefore a skeleton is necessary to support the tissues of large animals.

9. The Origin of Animals Aquatic, Colonial (multicellular), Heterotrophic Protists

10. The key to the success (survival ) of the Animals is their Diversity….their variations. The Diversity of the Animals originates from the variations that occur in their: 1. Tissue Complexity 2. Body Symmetry 3. Cephalization 4. GastroVascular Cavities (GVC) 5. Coeloms 6. Segmentation, and whether they are….. 7. Protostomes or Deuterostomes.

11. 1. Tissue Complexity Most animals, collectively called the eumetozoans, have closely functioning tissues. Some organisms are diploblastic, have only two cell layers… such as the hydra and jellyfish. Some organisms are triploblastic and have three cell layers. The three “germ layers” are the ectoderm, mesoderm and endoderm. There is a group of animals, the parazoans (sponges) that are not organized into true tissue and lack organs.

12. The Embryonic “Germ” Layers The three layers of tissues that become established during early embryonic development are called germ layers. They give rise to the body tissues. These three layers are called….. 1. ectoderm, 2. mesoderm, and 3. endoderm.

13. The Embryonic Germ Layers develop from the Blastula….. Gastrula

14. The Embryonic Germ Layers The ectoderm forms from the outer layer of cells. It gives rise to the skin, hair, nails and nervous system. mesoderm forms between the ectoderm and endoderm. It becomes the muscles, connective tissues, skeleton, kidneys, circulatory and reproductive organs. The endoderm made of cells that form the tube-like structure in the gastrula. These cells will form the lining of the GVC and the major organs of the digestive system.

15. 2. Body SymmetryThere’s 3 basis shapes…1. asymmetry, 2. radial and 3. Bilateral symmetry

16. Asymmetry Asymmetrical animals have no pattern of symmetry. The simplest animals (sponges) are asymmetrical.

17. Radial Symmetry The body parts of a radially symmetrical animal are arranged around a central axis so that each part extends from the center. Animals that exhibit radial symmetry tend to be sessile (immobile). Radial symmetry allows them to reach out in all directions.

18. Bilateral Symmetry Only one cut along the longitudinal axis will produce identical halves of a bilaterally symmetrical animal. Bilateral symmetry is best for motile animals. Body Plan Includes Anterior (head) and Posterior (tail) ends Dorsal and Ventral surfaces “Right” and “Left” sides are mirror images

20. 3. CephalizationThe term “Cephalo” means “head”. In animals with bilateral symmetry, there is a greater increase in the nerve tissue concentrated in the anterior end (the head) as animals increase in complexity. For example, brains have formed with accessory organs for seeing, hearing, tasting, etc.

21. 4. Gastrovascular Cavity (GVC) GastroVascular Cavities (GVC) are areas where food is digested. If they have only one opening, the processing is limited. Two openings designate a digestive tract allowing food to be digested more thoroughly.

22. 5. Body Cavities The body cavity is a space that separates the gut and internal organs from the rest of the body. It isolates the internal organs from body-wall movements. It also bathes the internal organs in a liquid through which nutrients and wastes can diffuse.

23. The Arrangement of the  Ectoderm, Mesoderm, and Endoderm An acoelomate is an animal which does not have a coelom. A coelom is a body cavity which is completely lined with mesoderm.

24. Flatworms are Acoelomates

25. A pseudocoelomate animal has a body cavity (called a pseudocoelom) located between endoderm and mesoderm.

26. Roundworms are Pseudocoelomates

27. The body cavity of a coelomate animal (called a coelom) is located within the mesoderm.

28. Earthworms are Coelomates

29. 6. Segmentation Many animals have segmented body parts. In some cases the parts repeat over and over again, as with earthworms. In other animals, the segments are modified, such as with insects… they essentially have 3 segments…. the head, thorax and abdomen.

30. 7. Body PlansProtostomes or Dueterostomes?

31. Embryonic Development During early development, the fertilized egg divides, or cleavages, to produce a solid ball of cells. Then, cell migration results in a hollow ball called a blastula.

32. Embryonic Development Gastrulation – the development of the Germ Layers Some cells of the blastula migrate inward producing a gastrula. The opening is the blastopore. The internal cavity is called the archenteron.

33. Embryonic Development The Gastrula will become the gut (digestive tract) of the mature animal. In species that have a separate mouth and anus, the tube will eventually extend through the length of the embryo and fuse with the opposite side. One opening will become the mouth, the other will become the anus.

35. 6 Major Trends in Evolution multicellularity 2. development of tissues, first none (sponges), then 2 (cnidarians), then 3 3. development of symmetry, first none (sponges), then radial (cnidarians), then bilateral 4. development of a GVC(gut), first none (sponges), then sac-like (cnidarians, flatworms), then complete 5. development of a body cavity, first none (flatworms), then a pseudocoelom (roundworms), then a coelom 6. development of segmentation; segmentation evolved in protostomes (annelids and arthropods) independently of that which evolved in deuterostomes.

36. Evolution of Symmetry The evolutionary sequence progressed from asymmetrical animals to radial and then to bilaterally symmetrical animals.

38. Summary of Evolutionary Trends Symmetry Asymmetry Radial Bilateral Gut No Gut Saclike Complete Coelom Acoelomate Pseudocoelomate Coelomate Embryonic Germ Layers None 2, (tissues, no organs) 3, (tissues and organs)

39. Evolutionary Trends

40. Classification of the Kingdom Animalia

41. Kingdom Animalia Survey

42. 1. Phylum Porifera(Sponges)

43. Phylum Porifera(Sponges)

44. 2. Phylum Cnidaria Jellyfish, Corals, and other Stingers

45. General Characteristics Simple body plan-bag shaped organism Radially symmetrical organization Consists of a mouth and a sac-like cavity Lacks an anus The mouth is surrounded by a ring of tentacles The cavity in the center of the gut, called the gastrovascular cavity.

46. Two Body Forms Polyps - attached to a surface - ex: sea anemones - mouth points up Medusae - free floating -ex: jellyfish -mouth points down

47. The Tissue Layers

48. 3. Phylum Platyhelminthes(Flatworms) Platyhelminthes consists of three kinds of acoelomate flatworms. 1. Free-living Flatworms: such as planarians, which are carnivorous scavengers. 2. Flukes: are internal, or external, parasites that suck tissue fluids or blood. 3. Tapeworms: internal parasites that live in the intestinal tracts of vertebrates.

49. Planaria

51. 4. Phylum Nematoda(Roundworms) • Found in fresh water, marine, moist soil, tissues of plants, and tissues and body fluids of animals • A complete digestive tract is present and nutrients are transported through the body in the pseudocoelomic fluid. • Free-living forms are important in decomposition • Animal parasitic forms can be hazardous to health. (Trichinella spiralis in humans via undercooked infected pork)

52. Nematode

53. 5. Phylum Rotifera(Rotifers) Rotifers are small, mainly freshwater organisms, although some are marine and others are found in damp soil. Complete digestive system is present. Rotifer refers to the crown of cilia that draws a vortex of water into the mouth.

54. Rotifer

55. 6. Phylum Mollusca(snails, bivalves (such as clams….have a shell which has two parts), octopuses and squids) In Squids, the shell is reduced and is internal. In octopuses, the shell is entirely absent. Octopuses have a highly developed nervous system with a large, complex brain.

56. Snails

57. 7. Phylum Annelid(Segmented Worms: includes leeches, earthworms and polychaetes) Earthworms ingest soil, extract nutrients in the digestive system and deposit undigested material (mixed with mucus from the digestive tract) as casts through the anus. Important to farmers as they till the soil and castings improve soil texture.

58. Phylum Annelid(Segmented Worms: includes leeches, earthworms and polychaetes)

61. 8. Phylum Arthropoda(spiders, insects, crustaceans, and various related organisms) Arthropods have two kinds of life cycles…(1) complete metamorphosis, (2) incomplete metamorphosis. Arthropods have: * jointed appendages, * a well-developed nervous system, * specialized body segments, and * an exoskeleton made of chiton.

63. Incomplete Metamorphosis (immature forms are often called nymphs) Nymphs resemble the adult in form except for being smaller and lacking fully developed wings and sexual organs. Life Cycle: Egg nymph adult 

64. Complete metamorphosisImmature forms are called larvae (larva, singular). The pupal stage is a transition stage, when the larva is transformed to the adult. Pupa molts to the adult form.  Life Cycle: Egg --> larva --> pupa --> adult 

65. 9. Phylum Echinodermata(sea stars (starfish), sea urchins and sand dollars) Echinoderms are Coelomates, Deuterostomes Echinoderms have complete digestive systems Although some adults exhibit radial symmetry, Some features are bilateral, as are the body shape of their larvae.

67. 10. Phylum Chordata The Phylum Chordata consists of animals that exhibit the following four features. In many cases, these features are temporary, appearing only during embryonic development.

68. 1. A Notochord A notochord provides support for the body. It is a flexible cord located on the dorsal surface. In most cases, the notochord is replaced by bone during development.

69. 2. A Dorsal Nerve Cord A dorsal nerve cord forms the basis of the nervous system. In some chordates, the nerve cord becomes the brain and spinal cord.

70. 3. Pharyngeal Gill Slits Pharyngeal Gill Slits provides channels across the pharynx to the outside of the body. In some chordates, the slits become gills for oxygen exchange, or for filter feeding, while in others, the slits disappear during embryonic development.

71. 4. A Muscular Tail A muscular tail extends beyond the digestive system. In many chordates, such as humans, the tail is lost during embryonic development.