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.
        How would you define the term 'line symmetry'?         Why might some people see line symmetry as 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 crabs and this starfish.
This type of symmetry is also called reflectional symmetry as the two parts reflect/match along each side of a dividing line ( or axis ).

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.
There are also many examples of symmetry inside the human body e.g. the lungs, the kidneys, the brain, the skull, etc.

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

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?