Presentation on theme: "Table of Contents What Is Life? Classifying Organisms"— Presentation transcript:
1 Table of Contents What Is Life? Classifying Organisms Domains and KingdomsThe Origin of Life
2 Life Comes From Life - What Is Life? Francesco Redi designed one of the first controlled experiments. In his experiment, Redi showed that flies do not spontaneously arise from decaying meat.
3 Life Comes From Life - What Is Life? Louis Pasteur’s carefully controlled experiment demonstrated that bacteria arise only from existing bacteria.
4 Using Prior Knowledge - What Is Life? Look at the section headings and visuals to see what this section is about. Then write what you already know about living things in a graphic organizer like the one below. As you read, write what you learn.What You KnowLiving things grow.Living things are made of cells.What You LearnedUnicellular organisms are composed of only one cell.The cells of living things are composed of chemicals.The cells of organisms use energy to do things they must do.
6 Levels of Classification - Classifying OrganismsLevels of ClassificationAs you move down the levels of classification, the number of organisms decreases. The organisms at lower levels share more characteristics with each other.
7 Aristotle and Classification - Classifying OrganismsAristotle and ClassificationMany hundreds of years before Linnaeus, a Greek scholar named Aristotle developed a classification system for animals. Aristotle first divided animals into those he considered to have blood and those he did not. This graph shows Aristotle’s classification system for “animals with blood.”
8 Aristotle and Classification - Classifying OrganismsAristotle and ClassificationReading Graphs:Into how many groups were these animals classified?3
9 Aristotle and Classification - Classifying OrganismsAristotle and ClassificationInterpreting Data:Which group made up the largest percentage of animals?Animals that fly
10 Aristotle and Classification - Classifying OrganismsAristotle and ClassificationCalculating:What percentage of these animals either fly or swim?78%
11 Aristotle and Classification - Classifying OrganismsAristotle and ClassificationInferring:In Aristotle’s classification, where would a cow be classified? A whale?Cow- animals that walk, run, or crawl; whale- animals that swim.
12 Aristotle and Classification - Classifying OrganismsAristotle and ClassificationPredicting:Would Aristotle’s classification system be used today? Explain.Possible answer: This system includes only three categories, so it may not be very useful today. It also does not match that of modern scientists, who use characteristics other than movement to classify animals. For example, frogsand lions belong tovery different groups.
13 Taxonomic Keys - Classifying Organisms Taxonomic keys are useful tools for determining the identity of organisms.
14 Evolution and Classification - Classifying OrganismsEvolution and ClassificationSpecies with similar evolutionary histories are classified more closely together. These Galapagos finches may have arisen from a single species and changed gradually over time to become three separate species. Notice the differences in their appearance, especially their beaks.eatseatseats
15 Asking Questions - Classifying Organisms Before you read, preview the red headings. In a graphic organizer like the one below, ask a what, why, or how question for each heading. As you read, write the answers to your questions.QuestionAnswerWhy do scientists classify?Scientists classify because they want to organize living things into groups so they are easier to study.What system did Linnaeus use to name organisms?He used a system called binomial nomenclature.What are the levels of classification?Domain, kingdom, phylum, class, order, family, genus, species
16 More on Classifying Living Things - Classifying OrganismsMore on Classifying Living ThingsClick the PHSchool.com button for an activity about classifying living things.
18 Three Domains of Life - Domains and Kingdoms In the three-domain system of classifications, all known organisms belong to one of three domains–Bacteria, Archaea, or Eukarya.
19 Comparing and Contrasting - Domains and KingdomsComparing and ContrastingAs you read, compare and contrast the characteristics of organisms in domains Bacteria, Archaea, and Eukarya by completing a table like the one below.Characteristics of OrganismsDomain or KingdomCell Type and NumberAble to Make Food?BacteriaProkaryotes; unicellularSome are able to make foodArchaeaProkaryotes; unicellularSome are able to make foodEukarya:ProtistsEukaryotes; unicellular or multicellularSome are able to make foodFungiEukaryotes; unicellular or multicellularNoPlantsEukaryotes; multicellularYesAnimalsEukaryotes; multicellularNo
20 Click the SciLinks button for links on kingdoms. - Domains and KingdomsLinks on KingdomsClick the SciLinks button for links on kingdoms.
22 The Atmosphere of Early Earth - The Origin of LifeThe Atmosphere of Early EarthOn ancient Earth, water vapor, carbon dioxide, and methane were probably the most abundant gases in the atmosphere. There were frequent volcanic eruptions, earthquakes, and violent storms.
23 Identifying Supporting Evidence - The Origin of LifeIdentifying Supporting EvidenceAs you read, identify the evidence that supports scientists’ hypothesis of how life arose on Earth. Write the evidence in a graphic organizer like the one below.EvidenceFossil evidence of achaea-like organismsHypothesisOrigin of lifeFossils dated to be between 3.4 and 3.5 billion years old.
24 Links on the Origin of Life Click the SciLinks button for links on the origin of life.