General characteristics

2. General characteristics • Eukaryotic • Multicellular • Heterotrophic • No cell wall • usually mobile in at least one stage of their life • produce sexually and produce an embryo Level of Organization Cells  Tissue  Organs  Organ systems  Animal

3. GeneralCharacteristics except Phylum Cnidaria- no mesoderm 2. Types of tissues epidermis and nervous system ectoderm outer layer circulatory, respiratory and skeletal systems mesoderm middle layer inner-most layer endoderm Digestive tract

4. Characteristics Symmetry and body plan • Asymmetrical body plan: irregular body shape • Radial symmetry: - can be divided into equal halves by a plane passing through the central axis in any direction • Bilateral symmetry: - body can be divided into equal halves only along a single plane - organisms with bilateral symmetry exhibit cephalization Our body symmetry?

5. ? Radial symm.

6. Cephalization • concentration of sensory organs and nerve cells at the anterior end • acts as a control centre • allows organism to respond to stimuli quickly • evolutionary favoured

7. GeneralCharacteristics Presence of a Body Cavity • Coelom: fluid-filled body cavity with organs suspended inside • Developed from mesoderm • Presence of compartments also means nutrients and O2 may not be diffused to every cells • Coelomates: animals with a coelom. • Acoelomates: animals without a coelom (e.g. corals, jelly fish and flatworms)

8. Advantages of a Coelom acts as a cushion for internal organs provides more room for internal organs to expand allows animal to become larger allows digestive tract to develop specialized regions and formation of blood vessels

9. GeneralCharacteristics Segmentation • The division of the body into repetitive sections e.g. worms and scorpions • A single segment can be damaged, but the other segments can continue to function properly • Mobility is more effective because segments move independently Movement • Complex and fast movement • Some are sessile (stationary) as adults e.g. sponges and sea anemones. They live attached to one place such as the bottom of the ocean or a rock. • Sessile animals have a body form that can move during juvenile stages of development

10. Recall • Zygote: cell formed after an egg is fertilized by a sperm • Gametes: sex cells like eggs and sperms • Diploid: containing two copies of each chromosome (2n) • E.g. A human zygote contains 46 chromosomes • Haploid: containing half the usual # of chromosomes (n) • E.g. Human eggs and sperms are gametes each contains ? chromosomes

11. GeneralCharacteristics Master of Cloning: https://www.youtube.com/watch?v=J7eRGHVx3p0 Reproduction • Sexually reproduction using gametes (haploid eggs and sperm meet to form a diploid zygote) • Internal (inside female body) or external (in aquatic environment) fertilization • Some animals switch between asexual and sexual modes, reserving sexual reproduction for when the conditions are tough Duck+ beaver + otter = platypus With shelled egg- bird, platypus Live birth- aphid, whale

12. Animal Evolution Cnidaria Nematoda Annelida Echinoderm Porifera Platyhelminthes Mollusca Arthropoda Chordata sponges jellyfish flatworms roundworms mollusks segmentedworms insectsspiders starfish vertebrates backbone segmentation endoskeleton coelom body cavity bilateral symmetry tissues multicellularity Ancestral Protist

13. Part II- Diversity in Animal Kingdom

14. Animal Diversity Porifera (sponges) Cnidaria

15. Porifera Sessile but living

16. Cnidaria

17. Animal Diversity Platyhelminthes (flat worm) Nematoda (round worms) Annelida (segmented)

18. Platyhelminthes ectoderm mesoderm endoderm Planaria regeneration http://www.youtube.com/watch?v=vXN_5SPBPtM Symmetry and cephalization observed in Planaria http://www.youtube.com/watch?v=w0QzSYQGsnA

19. Nematoda C. elegans • Roundworm: http://www.youtube.com/watch?v=DxL2qHBetvI • Guinea worm: http://www.youtube.com/watch?v=nu3z7mRyLRc

20. Nematoda • Loa loa is a filarial nematode (roundworm) species • Lives in human eyes- “eyeworm” • Hosts can feel the worm moving in the eye and can see it floating in there if it’s big enough. • easily killed using antibiotics or is extracted through minor surgery, though it can live inside a human for up to 17 years. http://www.liveleak.com/view?i=67a_1341408640&comments=1&use_old_player=0

21. Annelida- segmented worm fan worm leech

22. Animal Diversity mollusca echinodermata

23. Mollusks http://www.ted.com/talks/david_gallo_shows_underwater_astonishments.html

24. Animal Diversity crustaceans arachnida insecta Diploda / chilopoda

25. Insecta • Most successful invertebrate • Parasites hijack host behaviourthe case of parasitic wasp and catepillar http://www.youtube.com/watch?v=vMG-LWyNcAs

26. Echinoderms

27. Animal Diversity Tunicates + lancelets jawless fish cartilage fish bony fish amphibians reptilia aves mammalia

28. Tunicates and Lancelets

29. Sea Lamprey- jawless fish Parasitic eel-like creatures with suction-cup, bloodsucking mouths. Also an invasive species to the Great Lake ecosystem

31. Rays always look so cheerful!

32. Bony fish

33. Amphibians Gastric brooding frogs- now extinct

34. Disappearing of Froghttp://www.youtube.com/watch?v=ZWHibAQ0Ssohttp://animal.discovery.com/tv-shows/other/videos/the-vanishing-frog-with-jeff-corwin.htm 1. What proportion of amphibians are in trouble? - 30% 2. How long have amphibians been around? - 300 million years 3. What is the disease mentioned in the video that kills off amphibians? What is the cause of such disease? Chytrid disease caused by chytrid- an aquatic fungus that attacks frog’s skin. 4. What strategies have been done to increase frog number? • Treatment of frogs with antifungal drugs; captive breeding 5. Why should we be worried about frog’s disappearing? - their dual habitats (i.e. land and water) make them good indicators of healthy ecosystem; humans benefit from frog’s chemical; they are the link b/t terrestrial and aquatic food web

35. Birds- known for their feathers and …. Attitudes : Archaeopteryx Fossil record indicates birds and reptiles are closely related

36. Mamalian

37. 14 panda babies artificially bred in China http://www.bbc.co.uk/news/world-asia-china-24223721

38. The Worms Segmented worm Flatworm roundworm

39. The Worms bilateral bilateral bilateral

40. The Worms pseudocoelom (body cavity partially lined with mesoderm) Coelom (fluid filled space completely lined with mesoderm none

41. Body Cavity pseudocoelom coelom cavity ectoderm mesoderm endoderm acoelomate ectoderm mesoderm endoderm pseudocoelomate ectoderm mesoderm endoderm coelomate

42. The Worms 3 – ectoderm, mesoderm and endoderm 3 – ectoderm, mesoderm and endoderm 3 – ectoderm, mesoderm and endoderm

43. The Worms yes yes yes

44. The Worms One digestive opening (food and wastes through the same opening Separate anus and mouth Separate anus and mouth

45. The Worms Simple diffusion through gas exchange Yes – due to large size

46. The Worms Exhibit 2 forms of lifestyles: free-living and parasitic e.g. tapeworms Thin body wall and round shape minimize minimize outer surface area

47. The Worms Segments are identical - can increase in size without losing the capacity to transport materials and relay messages – segmentation improves movement / flexibility

48. Our evolutionary cousin http://youtu.be/G32YehcdUAw

49. Extra material

50. Classification • Invertebrates • Animals without backbones • Occupy almost all terrestrial and aquatic ecosystems • Have existed for hundreds of millions of years 2. Vertebrates • Phylum Chordata • Have a skull and a backbone that protects the nervous system (brain and spinal cord)