Classification and the 6 kingdoms

1. Classification and the 6 kingdoms

2. I. Taxonomy Taxonomy (Classification) is the branch of biology concerned with: A. Reconstructing phylogeny (evolutionary history) B. Naming organisms and placing them into hierarchical categories based upon their evolutionary relationships C. The eight major categories of classification, in order of decreasing inclusiveness are: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

4. Classification of the diversity of species is studied by: a) evolutionists b) taxonomists c) theorists d) taxidermists

5. II. History of Taxonomy • Aristotle’s System (more than 2,000 years ago) 1. He classified all living things known at that time into two major groups—plants and animals. 2. He grouped plants and animals according to their structural characteristics. 3. Plants were classified as trees, shrubs, and flowers. 4. Animals were grouped according to where they lived—on land, water, or air. 5. Later observations convinced scientists that Aristotle’s system did not work. They observed that some animals, such as frogs, lived both on land and in water. Scientists also realized that Aristotle’s classification system did not show natural relationships among organisms.

6. Aristotle

7. B. Carolus Linnaeus 1. An 18th century Swedish botanist developed a method of classification that is still used today, which is called binomial nomenclature. 2. Binomial nomenclature is a system by which each species is given a 2 word Latin name. 3. Linnaeus selected physical characteristics that led to classification based on close relationships of organisms. 4. Example for plants: He based his classification of flowering plants on the numbers and similarities of their reproductive structures. 5. Example for animals: He selected characteristics of organisms that also led eventually to classifications based on evolutionary relationships.

8. 6. Linaeus’ system uses 2 scientific names: a. The first part of the name is the genus— genus refers to the relatively small group of organisms to which a particular type of organism belongs. b. The second part of the name is the species- This is usually a description of some important characteristic. Example: Red Maple—common name Acer rubrum—scientific name (genus) (species)

10. C. Before 1969, all forms of life were classified into two kingdoms 1. Animalia 2. Plantae (included plants, bacteria, fungi and photosynthetic eukaryotes) D. Proposed by Robert H. Whittaker (1969) Kingdoms include: 1. Monera (all prokaryotes) 2. Plantae 3. Fungi 4. Animalia 5. Protista (eukaryotes that are not plants, fungi, or animals)

11. III. Scientific Names A. Common names are everyday names given to organisms. Common names may not accurately describe an organism. Example: Jellyfish is not a fish…but a Cnidarian. B. A scientific name is composed of the genus and the species. C. There are 3 rules to follow when writing scientific names: 1. Always capitalize the genus name. 2. Always leave the species in lowercase. 3. Always underline both names (unless typing...then use italics). Example: Home sapiens—Humans or if typing, Home sapiens Felisdomesticus—Cat Canisfamiliaris—Dog Rana pipiens—Frog

12. D. Trinomial nomenclature - when organisms can be divided even further into subspecies or varieties. Used when three scientific names are given. Ex: Acer rubrum var. drummondii is a Drummond’s red maple. Acer is the genus, rubrum is the species and drummondii is the variety of red maple that grows in the coastal plains area.

13. IV. Classification system of organisms from largest to smallest: This is the system most scientists use that puts each living thing into groups, organized from the most general to the most specific. Therefore, each species belongs to a genus, each genus belongs to a family, and each family belongs to an order. These are hierarchies. A. Domain:: Eukaryotic/Prokarytoic B. Kingdom:Inthe kingdoms, there are huge groups, encompassing millions of kinds of organisms in each. This group has the most, and as you go down, the number of different kinds of organisms decrease. In other words, the more specific it becomes.

14. C. Phylum or Division: A group of related classes. 1. Animal groups are called phyla. 2. Plant groups are called division. 3. All of the animals in the phylum vertebrata must belong to the same kingdom. 4. Chordata is to Animalia as phylum is to Kingdom. D. Class: A group of related orders. E. Order: A group of related families. F. Family: A group of closely related genera G. Genus: A group of similar species that are alike in general features and are closely related is a genus. Example: The leopard frog is know by the scientific name Rana pipiens. The wood frog is known as Rana sylvatica. What is the smallest classification division these frogs have in common? genus

15. H. Species: Species are the _most specific. A species consists of all the animals of the same type, who are able to breed and produce young of the same kind. 1. This biological classification group has the fewest members. 2. Organisms that look alike and successfully reproduce fertile offspring belong to the same species. 2 organisms would be most closely related if they are classified in the same species. 3. Ex: 2 plants probably belong to the same species if they can producefertile offspring.

17. 4. The biological species concept defines species as “groups of interbreeding natural populations, which are reproductively isolated from other such groups” -Cannot be applied to asexually reproducing organisms 5. Alternative species definitions have been proposed, one of which is the phylogenetic species concept a. The phylogenic species concept defines a species as “the smallest diagnosable group that contains all the descendants of a single common ancestor” b. Can be applied to sexually and asexually reproducing organisms c. May eventually replace the biological species concept

18. I. The more categories two organisms share, the closer their evolutionary relationship J. Today, scientists classify organisms according to the 1. Evolutionary history of the species. 2. The external and internal characteristics of organisms and 3. Chemical makeup—DNA (the genetic material). This is the best way to determine any taxonomic relationship between 2 organisms.

20. A group of related organisms that are able to interbreed in nature & produce fertile offspring is a: a) species b) phylum c) genus d) order

21. The taxonomic group that shows the greatest similarity among its members is the: a) kingdom b) class c) species d) family

22. Which statement describes organisms that are classified in the same genus? a) They must be in the same phylum, but may be of a different species. b) They must be of the same species, but may be in different phyla. c) They must be in the same kingdom, but may be in different phyla. d) They must be in the same class, but may be in different phyla.

23. As we move through the taxonomic groups from the kingdom to the species level, organisms: a) become more similar in appearance b) vary more & more c) are less related to each other

24. Which of these taxonomic classification groups has the fewest members? a) species b) family c) class d) genus

25. Classification of Humans: • Kingdom: Animalia • Phylum: Chordata • Class :Mammalia • Order:Primate • Family:Hominidae • Genus:Homo • Species: sapiens

27. Spurge Cactus

28. V. Taxonomy Reveals Evolutionary History A. Linnaeus’s classification system was based on the fact that organisms have different degrees of similarities. Ex: Tigers resemble gorillas more closely than they resemble fish. B. According to Darwin’s views, organisms that are similar descended from a common ancestor; therefore, classification provides strong evidence of evolution.

29. C. Making evolutionary connections based on similar traits can be misleading because not all traits are inherited from a common ancestor. Ex: The wings of a bird and the wings of an insect. Both enable flight, but the two kinds of wings are built differently, and based on fossil evidence, we know they evolved independently of each other. D. Convergent evolution is when organisms evolve similar features independently, often because they live in similar habitats. 1. Convergent evolution is the process by which unrelated species become similar as they adapt to similar environments. Similar features that evolved through convergent evolution are called analogous structures or homoplasies. 2. Ex: Although they evolved in differently whales on land and fish in water, whales and fish have similar structures.

30. The scientific name for the fruit fly is Drosophila melanogaster. The word Drosophila refers to the taxonomic group: a) kingdom b) genus c) species d) phylum

31. Scientists use a 2-name method of providing scientific names to organisms that is called: a) binomial nomenclature b) scientific nomenclature c) theoretical nomenclature

32. The scientific name of an organism: a) varies according to the native language of scientists. b) is the same for scientists all over the world. c) may refer to more than 1 species. d) is different for scientist all over the world.

34. The language of scientific names is: a) English b) Latin c) Spanish d) French

35. Of the following, Felis leo, is most closely related to: a) Rana pipiens b) Xenopus laevis c) Felis domesticus d) Elephas maximus

36. Scientific names come from the taxonomic groups: a) kingdom & phylum b) class & family c) genus & species d) order & family

37. E. Unique characteristics help distinguish groups: 1. Modern taxonomists use the phylogeny (evolutionary history) of an organism to classify it. 2. A phylogenetic tree is a family tree that shows the evolutionary relationship thought to exist among groups of organisms. Scientists construct a phylogenetic tree by using several lines of evidence such as: a. fossil records b. An organism’s morphology compared to the morphology of other living things c. Embryological patterns of development d. Comparisons of macromolecules such as DNA, RNA, and proteins as well as an organism’s biochemistry.

39. F. Cladistic taxonomists use derived characters to establish evolutionary relationships 1. Derived characteristic -feature that evolved only within the group under consideration. 2. Example: a derived character for birds is feathers.

41. The red maple tree is known by the scientific name Acer rubrum. The sugar maple tree is known as Acer saccharum. What is the smallest classification division these trees have in common? a) phylum b) order c) genus d) species

42. It is easy to group snakes based on color. However, a scientist would prefer a system that shows how snakes: a) get their food b) shed their skin c) are genetically related d) mate

43. G. Many taxonomists give varying degrees of importance to characters and thus produce a subjective analysis of evolutionary relationships called evolutionary systematics. 1. Evolutionary systematics is the approach of choice when a great deal of information about a group of organisms is available. When little information is available about how a character affects the life of an organism, cladistics is the better choice. 2. Ex: Evolutionary systematics places birds in an entirely separate class from reptiles, which gives more importance to characters like feathers that made powered-flight possible. H. Dichotomous keys: tool used by scientists to classify organisms, using a system of questions. Ex:

45. VI. Biodiversity A. The total number of species in an ecosystem B. Number of named species is currently about 1.5 million (biased toward large organisms in temperate regions) a. 5% prokaryotes and protists b. 22% plants & fungi c. 73% animals C. Estimated that 7 million to 10 million species may exist D. Between 7,000 and 10,000 new species are identified annually, mostly in the tropics E. Tropical rain forests are believed to be home to 2/3 of the world’s existing species, most of which have yet to be named F. Because tropical rain forests are being destroyed so rapidly, species may become extinct before we ever knew they existed

46. There is a six-kingdom classification system: 1. Kingdom Archeabacteria 2. Kingdom Eubacteria 3. Kingdom Protista 4. Kingdom Fungi 5. Kingdom Plantae 6. Kingdom Animalia Kingdoms 1 and 2 used to be combined into Kingdom Monera

49. I. Both Archaebacteria and Eubacteria: (_MONERANS) A.Both are prokaryotes—_DO NOT HAVE A NUCLEUS OR MEMBRANE BOUND ORGANELLES B. Small (microscopic), simple, and lack membrane-bound organelles. C. DNA is found _FLOATING IN THE CYTOPLASM_. D. Most _UNICELLULAR_ (1 cell) • Most numerous and widespread organisms on the earth

50. F. Both reproduce by _BINARY FISSION_. 1. The cell pinches into 2 cells, 2. a form of asexual reproduction that produces identical offspring. 3. In asexual reproduction, a single parent passes exact copies of its entire DNA to its offspring. 4. Binary fission can occur every 20 minutes 5. Rapid reproductive rate allows for rapid evolution 6. Mutations in DNA replication are rapidly spread