Classification:

1. Classification: Georgia Performance Standards: SB3. Students will derive the relationship between single-celled and multi-celled organisms and the increasing complexity of systems. b. Compare how structures and function vary between the six kingdoms (archaebacteria,eubacteria, protists, fungi, plants, and animals). c. Examine the evolutionary basis of modern classification systems. d. Compare and contrast viruses with living organisms. SB5. Students will evaluate the role of natural selection in the development of the theory of evolution. e. Recognize the role of evolution to biological resistance (pesticide and antibiotic resistance).

2. Essential Questions: • How does the evidence of evolution contribute to modern classification systems? • Why classify? • On what criteria do Taxonomists base their classification of organisms? • Are viruses alive? • What is the role of evolution in antibiotic and pesticide resistance?

3. Why Classify? • To study the diversity of life, biologists use a classification system to name organisms and group them in a logical manner. • In taxonomy, scientists classify organisms and assign each organism a universally accepted name. • By using a scientific name, biologists can be certain that everyone is discussing the same organism.

4. Early Efforts at Naming Organisms • The first attempts at standard scientific names often described the physical characteristics of a species in great detail. • Results in long names • Difficult to standardize the names of organisms • Different scientists described different characteristics.

5. Binomial Nomenclature • Carolus Linnaeus developed a two-word naming system called binomial nomenclature. • In binomial nomenclature, each species is assigned a two-part scientific name. • First word is the genus • Second word is the species

6. Organizing Life’s Diversity Chapter 17 17.1 The History of Classification • When writing a scientific name, scientists use these rules: • The first letter of the genus name always is capitalized, but the rest of the genus name and all letters of the specific epithet are lowercase. • If a scientific name is written in a printed book or magazine, it should be italicized. • When a scientific name is written by hand, both parts of the name should be underlined. • After the scientific name has been written completely, the genus name will be abbreviated to the first letter in later appearances (e.g., C. cardinalis).

7. A group or level of organization is called a taxonomic category, or taxon King Phillip Came Over From Genoa Spain The are 7 taxonomic categories. (from smallest to largest) species genus family order class Phylum kingdom. Domain Linnaeus's System of Classification

8. The 7 taxonomic categories • Species - a group of organisms that breed with one another and produce fertile offspring. • Genus - a group of closely related species. • Family- genera that share many characteristics. • Order - is a broad taxonomic category composed of similar families. • Class- is composed of similar orders. • Phylum- several different classes that share important characteristics. • Kingdom - largest taxonomic group, consisting of closely related phyla

10. Classification Pop Quiz: 1. How are living things organized for study? 2. Describe the system for naming species that Linnaeus developed. 3. What are the seven taxonomic categories of Linnaeus’s classification system from largest to smallest? 4. Why do scientists avoid using common names when discussing organisms? 5. Based on their names, you know that the baboons Papioannubis and Papio cynocephalus do NOT belong to the same a. Class b. family c. Genus d. species

11. Modern Evolutionary Classification  • Organisms are grouped into categories that represent lines of evolutionary descent, not just physical similarities • This strategy of grouping organisms together based on their evolutionary history is called evolutionary classification. • Modern classification systems are based upon biochemical and genetic evidence that indicates evolutionary relationships

12. How do we determine evolutionary relationships? 1. Look for structural similarities. 2. Look at breeding behavior. 3. Look at geographic distribution and find where organism are located and their range. 4. Look at Chromosomes for similar structure and number. 5. Look at biochemistry: Look for similar DNA sequences and therefore similar proteins

13. Phylogenetic Classification • Phylogeny: the evolutionary history of a species. • Phylogenetic classification is a classification system that shows the evolutionary history of a species. • Cladistics: It is assumed that a group of organisms diverged and evolved from a common ancestral group. • Derived traits: Characteristics of the original group that are retained.

14. Classification Using Cladograms • Cladistic analysis identifies and considers only the characteristics that arise as lineages evolve over time. • Characteristics that appear in recent parts of a lineage but not in its older members are called derived characters. • Derived characters can be used to construct a cladogram, a diagram that shows the evolutionary relationships among a group of organisms.

15. Traditional Classification Versus Cladogram Section 18-2 Appendages Conical Shells Crustaceans Gastropod Crab Crab Limpet Limpet Barnacle Barnacle Molted exoskeleton Segmentation Tiny free-swimming larva TRADITIONAL CLASSIFICATION CLADOGRAM Go to Section:

16. Cladogram: a branching diagram using cladistics. • Image taken from:http://evolution.berkeley.edu/evolibrary/article//evo_03

17. Organizing Life’s Diversity Chapter 17 17.2 Modern Classification Cladograms • The greater the number of derived characters shared by groups, the more recently the groups share a common ancestor.

18. Molecular Clocks Comparisons of DNA can also be used to mark the passage of evolutionary time. A model known as a molecular clock uses DNA comparisons to estimate the length of time that two species have been evolving independently. Comparison reveal how dissimilar the genes are. Degree of dissimilarity is an indication of how long ago the two species shared a common ancestor. Modern Evolutionary Classification

19. Checkpoint Questions: • How is information about evolutionary relationships useful in classification? • How are genes used to help scientists classify organisms? 3. What is the principle behind cladistic analysis? 4. Describe the relationship between evolutionary time and the similarity of genes in two species. 5. How have new discoveries in molecular biology affected the way in which we classify organisms compared with the system used by Linnaeus? Constructing a Chart  

20. Kingdoms and Domains  • The six-kingdom system of classification includes the following kingdoms: • Eubacteria • Archaebacteria • Protista • Fungi • Plantae • Animalia.

21. The Three-Domain System • The domain is the most inclusive taxonomic category; larger than a kingdom  • The three domains are: • Bacteria : kingdom Eubacteria • Archaea,: kingdom Archaebacteria; • Eukarya :Kingdom protists, fungi, plants, and animals.

22. Key Characteristics of Kingdoms and Domains Classification of Living Things Eukarya Bacteria Eubacteria Prokaryote Cell walls with peptidoglycan Unicellular Autotroph or heterotroph Streptococcus, Escherichia coli Protista Eukaryote Cell walls of cellulose in some; some have chloroplasts Most unicellular; some colonial; some multicellular Autotroph or heterotroph Amoeba, Paramecium, slime molds, giant kelp Archaea Archaebacteria Prokaryote Cell walls without peptidoglycan Unicellular Autotroph or heterotroph Methanogens, halophiles DOMAIN KINGDOM CELL TYPE CELL STRUCTURES NUMBER OF CELLS MODE OF NUTRITION EXAMPLES Plantae Eukaryote Cell walls of cellulose; chloroplasts Multicellular Autotroph Mosses, ferns, flowering plants Fungi Eukaryote Cell walls of chitin Most multicellular; some unicellular Heterotroph Mushrooms, yeasts Animalia Eukaryote No cell walls or chloroplasts Multicellular Heterotroph Sponges, worms, insects, fishes, mammals Go to Section:

23. Eukaryotic cells Prokaryotic cells Kingdom Plantae Kingdom Protista Domain Bacteria Domain Archaea Kingdom Fungi Kingdom Animalia Kingdom Eubacteria Kingdom Archaebacteria Section 18-3 Living Things are characterized by Important characteristics which place them in and differing Domain Eukarya Cell wall structures such as which is subdivided into which place them in which coincides with which coincides with Go to Section:

24. The Six Kingdoms • Kingdom Archaebacteria: Bacteria that live in extreme environments void of oxygen. Cell membrane lipids, RNA, and cell wall structures are different than other bacteria. • Kingdom Eubacteria: all other bacteria. Strong cell walls and less complicated genetic makeup. Live in many habitats • Kingdom Protista: Eukaryote that lacks complex organ systems and lives in moist environments. Can be unicellular or multicellular

25. The Six Kingdoms Continued • Kingdom Fungi: Heterotrophs that do not move from place to place. Uni or multicellular eukaryotes that absorb nutrients from organic material. • Kingdom Plantae: Multicellular photosynthetic eukaryotes. Can not move from place to place. Cells organized into tissues, tissues organized into organs. • Kingdom Animalia: Animals: multicellular heterotrophs. Able to move from place to place. No cell walls. Cells form tissues that form organs that form organ systems.

26. Organizing Life’s Diversity Chapter 17 17.3 Domains and Kingdoms Domain Archaea • Archaea are thought to be more ancient than bacteria and yet more closely related to our eukaryote ancestors. • Archaea are diverse in shape and nutrition requirements. • They are called extremophiles because they can live in extreme environments.

27. Organizing Life’s Diversity Chapter 17 17.3 Domains and Kingdoms Domain Bacteria • Eubacteria are prokaryotes whose cell walls contain peptidoglycan. • Eubacteria are a diverse group that can survive in many different environments.

28. Bacteria and Viruses Chapter 18 18.1 Bacteria Mutations • Bacteria reproduce quickly and their population grows rapidly. • Mutations lead to new forms of genes, new gene combinations, new characteristics, and genetic diversity. • Rapid mutations cause bacteria to become resistant to many antibiotics and pesticides.

29. Organizing Life’s Diversity Chapter 17 17.3 Domains and Kingdoms Domain Eukarya • All eukaryotes are classified in Domain Eukarya. • Domain Eukarya contains Kingdom Protista, Kingdom Fungi, Kingdom Plantae, and Kingdom Animalia.

30. Protists are eukaryotic organisms that can be unicellular, colonial, or multicellular . Organizing Life’s Diversity Chapter 17 17.3 Domains and Kingdoms Kingdom Protista • Protists are classified into three different groups—plantlike, animal-like, and funguslike.

31. A fungus is a unicellular or multicellular eukaryote that absorbs nutrients from organic materials in its environment. Organizing Life’s Diversity • Member of Kingdom Fungi are heterotrophic, lack motility, and have cell walls. Chapter 17 17.3 Domains and Kingdoms Kingdom Fungi

32. Organizing Life’s Diversity • Most plants are autotrophs, but some are heterotrophic. Chapter 17 17.3 Domains and Kingdoms Kingdom Plantae • Members of Kingdom Plantae form the base of all terrestrial habitats. • All plants are multicellular and have cell walls composed of cellulose.

33. Organizing Life’s Diversity Chapter 17 17.3 Domains and Kingdoms Kingdom Animalia • All animals are heterotrophic, multicellular eukaryotes. • Animal organs often are organized into complex organ systems. • They live in the water, on land, and in the air.

34. Organizing Life’s Diversity Chapter 17 17.3 Domains and Kingdoms Viruses—An Exception • A virus is a nucleic acid surrounded by a protein coat. • Viruses do not possess cells, nor are they cells, and are not considered to be living. • Because they are nonliving, they usually are not placed in the biological classification system.

35. Characteristics of Viruses: • Viruses are not cells • Viruses are not alive • Viruses do not use energy • Viruses can reproduce only when inside living cells • Viruses do contain genetic info. & can evolve over time.

36. Defenses Against Viruses: • Why can’t we treat viral diseases with antibiotics? • Vaccinations also protect against some viral diseases. • Harmless viruses stimulate the immune system to create defenses against the harmful form of the virus. • Vaccines only work on viruses whose surface proteins do not change (mutate). (Small pox, measles, polio) • HIV, cold viruses, and flu viruses (genes mutate too often for vaccines to become effective)

37. Checkpoint Questions: • What are the six kingdoms of life as they are now identified? • What are the three domains of life? 3. Why was the kingdom Monera divided into two separate kingdoms? 4. Why might kingdom Protista be thought of as the “odds and ends” kingdom? 5. Which kingdoms include only prokaryotes? Which kingdoms include only heterotrophs?

38. Dichotomous Keys • A tool used to identify organisms is a dichotomous key. • A dichotomous key is a series of paired statements that describe physical characteristics of different organisms. • In this activity, you will use a dichotomous key to identify tree leaves.