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Let ’ s Classify!!! PowerPoint Presentation
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Let ’ s Classify!!!

Let ’ s Classify!!!

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Let ’ s Classify!!!

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  1. Let’s Classify!!!

  2. What does it mean to classify? • Could you imagine your closet or your drawers in your room not being organized? • What if you just threw the kitchen utensils into a drawer? • Puts order into a system or group • Give some examples from your life where you have formed a classification system to make your life easier

  3. The Dichotomous Key • Is the object round? Yes go to 2; no go to 3 • Is it 3-D (go to 4) or 2-D (go to 5)? • Does it have 4 equal sides? Yes = SQUARE; no go to 6 • SPHERE • CIRCLE • Does it have 2 equal sides? RECTANGLE

  4. Dichotomous Key Is a method for determining the identity of something by going through a series of choices that leads the user to the correct name of the organism. Dichotomous means "divided in two parts". At each step of the process of using the key, the user is given two choices; each alternative leads to another question until the item is identified

  5. Candy Dichotomous Key • a. packaged go to step 2 b. un-packaged go to step 3 • a. boxed Sugar Babies b. wrapper go to step 4 • a. soft Gummy Bears b. hard go to step 5 • a. plastic wrapper go to step 10 b. wax paper wrapper go to step 6 • a. round shaped go to step 7 b. not round shaped Mike and Ikes • a. on a stick Dum Dum Lollipops b. not on a stick Tootsie Rolls • a. sphere-shaped go to step 8 b. oval-shaped go to step 9 • a. multi-colored Gobstoppers b. pale yellow colored Unpackaged Lemon Heads 9. a. circular shaped(should be marked with an “s”) Skittles b. A little less circular shaped (should be marked with an “m”) M&M’s 10. a. red-colored candy Atomic Fireball b. yellow-colored candy Packaged Lemon Heads

  6. Dichotomous key • Uses a branching system of two features to separate steps. Helps in identification process • 1A. With hair Mammal • B. Without hair Go to 2 • 2A. Has scales Go to 3 • B. Does not have scales Go to 4 • 3A. Has a three chambered heart Reptiles • B. Has a two chambered heart Fish • 4A. Has feathers Birds • B. Does not have feathers Amphibians

  7. 1a. Wings covered by an exoskeleton…..... Go to 2 b. Wings not covered by an exoskeleton …Go to 3 2a. Body has a round shape………….......Ladybug b. Body has an elongated shape.......Grasshopper 3a. Wings fold against body......................Housefly b. Wings point out from sides……..…….Dragonfly

  8. 1 2 3 5 7 4 6 8 9 10

  9. Classification of Organisms aardvark armadillo pangolin??? sloth

  10. Why Do Scientists Classify Organisms? • To identify them • To communicate universally • To learn about their characteristics • To understand relationships

  11. Chapter 17: Classification of Organisms

  12. 17.1 Biodiversity: Taxonomy • Field of biology that describes, names and groups (classifies) organisms according to their characteristics • A taxon (taxa, plural) is a group • There are several different taxa at different levels

  13. Classification systems • 1st system – Aristotle’s grouped plants and animals by land, sea and air – 2400 years ago – what was problematic with his system, and why did he do what he did? • Early systems had naming issues – common names such as rose, jellyfish • Modern system - Carolus Linnaeus (1707 – 1778) – animal, vegetable, mineral

  14. Some past systems

  15. Modern system is based on morphological similarities – let’s look at human classification • Hierarchy of eight groups (Taxa) • Domain – New taxon - Eukarya • Kingdom – largest most inclusive grouping- Animalia • Phylum (Division in plants)- Chordata • Class - Mammalia • Order - Primate • Family - Hominidae • Genus – Homo • Species – most exclusive, specific group. Members of this grouping can mate and produce viable offspring – sapiens • Varieties – same species but with slight differences - plants - Subspecies – same species, different location

  16. Here is mnemonic for you… King Philip Came Over From Great Spain

  17. What’s in a name? • Binomial nomenclature – each species in given a two part name Ex. Homo sapiens • Genus name – Homo orHomo • Species name – Homo sapiens • Species identifier – usually descriptive - sapiens or sapiens • **Latin is the language of classification – universal and does not evolve (dead language)

  18. 17.2 Systematics: Some Terminology • Taxonomy NAMES Ex. Rosa rogusa • Classification GROUPS according to morphology Ex. Plant kingdom • Systematics (phylogeny) GROUPS according to evolutionary relationships Ex. Closely related to Rosa multiflora

  19. Some terminology, cont. • Systematics – includes the definition of taxonomy PLUS organizes living things in the context of evolution – it includes • Phylogeny – the study of evolutionary relationships – different than the tree of life • Use morphology, ontogeny (embryological development), biomolecules, geography, fossil record

  20. Blastopore Zygote Morula Blastula

  21. Phylogenetic Diagram

  22. Cladistics • Phylogeny that uses certain features called derived characters to show evolutionary relationships • Shared characters – body coverings such as hair, fur, scales, feathers • Derived characters – unique feature to a group (feathers in birds) • Cladistics uses groupings called clades to place organisms into who have a COMMON ANCESTOR, plus all of their descendants

  23. Cladograms, cont. • A cladogram is a useful way of organizing, in a visual way, the relationships between creatures that share and do not share derived characters. • Construction begins with data; a table of traits or characteristics that have evolved or been derived by the evolutionary process.

  24. Amoeba Sponge Earthworm Salmon Lizard Kangaroo Cat Placenta Hair Limbs Jaws Segmented Multicellular

  25. Monotreme mammals Marsupial mammals Placental mammals Fish Amphibians Reptiles Birds Warm-blooded Placenta Early Internal development Hair Amniotic egg Lungs

  26. http://ccl.northwestern.edu/simevolution/obonu/cladograms/Open-This-File.swfhttp://ccl.northwestern.edu/simevolution/obonu/cladograms/Open-This-File.swf http://www.bu.edu/gk12/eric/cladogram.pdf

  27. The Role of Biomolecules • The molecular clock – uses amino acids, proteins, DNA, RNA to determine how closely related organisms are; the more differences, the farther back in time they shared a common ancester

  28. Biomolecules, cont. • Chromosomes and karyotypes

  29. Putting It All Together Figure 17-7 in your text, page 345 Not the anteater or sloth, but the bear and cat!!!

  30. 17.3 Modern Classification: Where are we now?

  31. Archaebacteria • Many live in harsh environments (extremophiles) • – Archae – Ancient • Asexually reproduces by binary fission

  32. Eubacteria • Eu – true • Most of the bacteria belong here • Asexually reproduces by binary fission

  33. Protista • Pro – first • Plant-like, Animal-like and Fungus-like characteristics. • Least clear cut of all kingdoms. • Asexually by binary fission & segmentation

  34. Fungi • Absorptive heterotrophs • Cell walls made of chitin • Reproduces sexually and asexually

  35. Plantae • Multicellular • Photosynthetic organisms • Cell wall made of cellulose • Reproduces asexually and sexually

  36. Animalia • Multicellular • Ingestive heterotrophs • Reproduces asexually and sexually

  37. Three - Domain System • Woese compared rRNA to show that living things can be grouped into 3 groups/domains • The domains: Bacteria (Eubacteria) Archaea(Archaebacteria) Eukarya (Everything else)

  38. Overall Phylogenetics

  39. Human Classification: • Domain - Eukarya • Kingdom – Animalia • Phylum – Chordata • Class – Mammalia • Order – Primate • Family – Hominidae • Genus – Homo • Species – sapiens