Symmetry: A Visual Presentation

1. Symmetry:A Visual Presentation

2. Bilateral Symmetry • Bilateral symmetry occurs when one half of an object is the mirror image of the other half. • Symmetry exists all around us and many people see it as being a thing of beauty.

3. Is a butterfly symmetrical?

4. At the  beach there are a variety of shells with symmetry.

5. Under the sea there are also many symmetrical objects such as these crabsand this starfish.

6. Animals that have bilateral symmetry

7. THESE MASKS HAVE bilateral SYMMETRY These masks have a line of symmetry from the forehead to the chin. The human face also has a line of symmetry in the same place.

8. Human Bilateral Symmetry The 'Proportions of Man' is a famous work of art by Leonardo da Vinci that shows the symmetry of the human form.

9. Classification 4.1: Classify animals according to type of skeletal structure, method of fertilization & reproduction, body symmetry, body coverings, & locomotion.

10. Phylum Porifera: asymmetrical • Invertebrate, no body tissues or organs • Filter feeders • Reproduce sexually w/fertilization & asexually by budding • Do not move as adults—only when budding

11. Phylum Porifera: the sponges • This is what a sponge looks like; notice the range of colors.

12. A sponge doesn’t look this. Phylum Porifera • A sponge reproducing asexually through budding.

13. Phylum Cnidaria: corals & anemones • Invertebrates • Have stinging cells (pneumatocysts) for hunting & protection • Ingest food into a central body cavity • Radial symmetry • Many adults can move to escape danger or get food • External sexual reproduction • Asexual reproduction through budding

14. Phylum Cnidaria: corals and anemones • Notice the crab inside Clownfish here

15. Phylum Cnidaria: corals and anemones • Brain coral • Notice the radial symmetry

16. Worms are in 3 different phyla • 1. Flatworms = Phylum Platyhelminthes • 2. Roundworms = Phylum Nematoda • 3. Segemented worms = Phylum Annelida

17. Worms • Invertebrates • Long bodies with no legs • Bilateral symmetry • Possess tissues, organs, and organ systems • Reproduce sexually and asexually

18. Flatworms: Phylum Platyhelminthes

19. Roundworms: Phylum Nematoda

20. Segmented Worms: Phylum Annelida

21. Phylum Mollusca: the mollusks • Invertebrates • Soft, unsegmented bodies often covered by a shell • Bilateral symmetry • 3 major groups: gastropods, bivalves, cephalopods

22. Phylum Mollusca: the mollusks, gastropods • Example: snails • Have single external shell or no shell at all • Move by use of a muscular foot

23. Phylum Mollusca: the mollusks, gastropods

24. Phylum Mollusca: the mollusks, bivalves • 2-shelled mollusks that filter feed • Examples: oysters, clams, scallops • Adult bivalves stay in one place or move slowly through the water

25. Phylum Mollusca: the mollusks, bivalves • Scallop Oysters

26. Phylum Mollusca: the mollusks, cephalopods • Examples: octopus, squid, cuttlefish, nautilus • Ocean-dwelling w/a “foot” adapted to form tentacles around its mouth • Not all have shells • Capture prey by using tentacles • Swim with jet propulsion

27. Phylum Mollusca: the mollusks, cephalopods • Squid, nautilus, cuttlefish, and octopus

28. Birds are in the Phylum Chordata • Endothermic (produce & maintain body heat) • Vertebrate w/4 chamber hear • Bodies covered w/feathers • MOST can fly using their wings • Puffins, penguins, kiwi, rheas, emus, & ostriches don’t • Internal, sexual reproduction & lay eggs • Bilateral symmetry • Parents care for babies until they can fly

29. Bird examples • Kiwi Emu Puffin (can fly but doesn’t usually)

30. Mammals are in the Phylum Chordata • Endothermic • Vertebrate w/4 chamber heart • Skin covered w/fur or hair • Most born live & nursed with mother’s milk • Most walk or run on 4 limbs • Bilateral symmetry • Reproduce with internal, sexual reproduction

31. Mammals are in the Phylum Chordata • Classified into 3 groups based on how their young develop • Monotremes • Marsupials • Placentals • Mammals care for young for an extended time.

32. Mammals: monotremes • most primitive mammals • There are three species of monotremes, the duck-billed platypus (Ornithorhynchus) and two spiny anteaters, or echidnas (Tachyglossus and Zaglossus). • These mammals lay eggs; after the babies hatch, the mothers nourish their young with milk. • Today, monotremes live only in Australia and New Guinea. • The name monotreme means "one-holed," referring to the cloaca, a single hole that serves the urinary tract, anus, and reproductive tract in monotremes.

33. Monotremes • Duck-billed platypus Echidna

34. Marsupial Mammals • Marsupials (Megatheria) are pouched mammals whose babies are born in a very undeveloped state; the young then attach themselves to their mother's nipple. • Many marsupials have a pouch that encloses the young. • The biggest marsupial is the human-sized red kangaroo (Macropus rufus); the smallest marsupial, the pilbara (Ningaui timealeyi), would fit in a person's hand. • Some commonly-known marsupials include the kangaroo, opossum, Tasmanian devil, and koala. The only marsupial in North America is the Virginia opossum. • Marsupials evolved during the late Cretaceous period, about 100 to 75 million years ago, during the time of the dinosaurs.

35. Marsupial Mammals • Virginia opossum Koala

36. Marsupial Mammals • 3-week old red kangaroo

37. Marsupial Mammals • The pilbara mouse, world’s smallest marsupial • Tasmanian devil

38. Phylum Arthropoda: the arthropods • Exoskeleton • Segemented body • Jointed appendages • Bilateral symmetry • Most reproduce sexually • Specialized mouth parts for chewing food • Move through use of legs

39. Phylum Arthropoda • Includes crustaceans, arachnids, centipedes, millipedes, and insects • Insects have wings for flying • Crustaceans include crabs and shrimp • Arachnids = spiders & ticks • Insects = mosquitoes, bees, grasshoppers, crickets

40. Phylum Arthropoda: Crustaceans • Woodlouse Crab • Shrimp

41. Phylum Arthropoda: Arachnids

42. Phylum Arthropoda: Centipedes and Millipedes • Centipedes with distinct poison fangs Millipedes

43. Phylum Arthropoda: insects

44. Objective 6.1: Describe protective adaptations of organisms, including mimicry, camoflage, and chemical defense.

45. Terms defined • Mimicry: defense strategy; an adaptation of an organism that allows it to look like a more dangerous one—see p. 727 in text • Camouflage: defense strategy/protection; an adaptation that provides organisms with the ability to blend in with their environments • Chemical defense: defense strategy/protection that allows organisms to poison predators if eaten or threatened; often are bright colored warning predators of poisnous nature

46. How many butterflies do you see?