Scientific names allow scientists to talk about particular species without confusion

Transcription

1 Unit 9 Test Review KEY a. Explain the history, purpose, and methods of taxonomy What is taxonomy? the science of naming and classifying organisms Who came up with it? Linnaeus Why do we use taxonomy? Scientific names allow scientists to talk about particular species without confusion On what basis is Linnaean classification determined? physical traits and characteristics b. Explain the significance of modern classification (binomial nomenclature) What is binomial nomenclature? a system that gives each species a two-part scientific name using Latin roots What can the genus tell you about similar organisms? that the species are closely related and most likely have similar characteristics How is an organism s scientific name written? in italics; genus is capitalized and species is left lowercase. Ex: Quercus alba is the genus and species for white oak. c. Classify organisms using dichotomous key Use a dichotomous key to identify organisms. Answers to practice dichotomous key on next page: 1. peacock flounder 2. spotted goat fish 3. glassy sweeper 4. squirrel fish 5. spotted eagle ray 6. band-tail puffer 7. spotted moray eel 8. glass-eye snapper 9. trumpet fish

2 d. Describe the organization of taxa in a biological classification system (DKPCOFGS) Be able to list the taxa from broadest to most specific. Domain, kingdom, phylum, class, order, family, genus, species e. Interpret a phylogenetic tree/cladogram to determine evolutionary relationships On what basis does a cladogram classify organisms?

3 common ancestry (evolutionary history) What is a derived character? The traits that can be used to figure out evolutionary relationships among a group of species are those that are shared by some species but are not present in others How can you tell if a species is closely related on a cladogram? They are closer together on the cladogram What is a clade? a group of organisms that all originate from a common ancestor that possesses some sort of derived character What is a phylogeny? the evolutionary history for a group of species f. Compare the characteristics of the six kingdoms of life (cell type, cell wall composition, feeding methods, levels of organization, and examples ) What are the 6 kingdoms? Animalia, Plantae, Fungi, Protista, Bacteria, Archaea What are the 3 domains? Eukarya, Bacteria and Archaea What 2 domains include prokaryotes? Bacteria and Archaea What are examples of kingdoms in the domain Eukarya? Animalia, Plantae, Fungi, Protista all contain organisms with EUKARYOTIC cells (cells with a nucleus) Which kingdoms are autotrophic? Plantae, some from Protista, some from Bacteria, some from Archaea What is the cell wall composition of plants? fungi? bacteria? Plantae cellulose; Fungi chitin; Bacteria peptidoglycan g. Identify the structure of a virus (capsid, viral envelope, genetic material) What is a capsid? protein coat on a virus that surrounds the DNA or RNA capsid nucleic acid lipid envelope surface proteins

4 Where is the genetic material in a virus? DNA or RNA never both Where can the viral envelope be found in a virus? Around the outside it s typically a lipid membrane h. Compare and contrast the reproductive cycles of viruses (lytic/lysogenic) What events occur in the cycle of a lytic virus? 1. virus infects host cell 2. virus injects its genetic material (DNA or RNA) into cell 3. Cell begins to make new viruses 4. Viruses burst out of cell (cell lyses, hence lytic cycle) What events occur in the cycle of a lysogenic virus? 1. virus infects host cell 2. virus injects its genetic material (DNA or RNA) into cell 3. Viral DNA or RNA combines into the DNA of the host cell 4. Host cell continues to multiply with the viral DNA. (You can think of this cycle as the virus is hibernating in the host it s not technically active until it goes into the lytic cycle) How are the two life cycles different? The lytic cycle kills the host cell and in the lysogenic cycle, the host cell is not killed Which cycle kills the host cell? lytic cycle i. Explain the relationship between the life cycle of viruses (such as HIV, influenza) and disease in a host When a person first contracts HIV, in what life cycle is the virus? lysogenic the virus is hibernating, the person is HIV+ but may not feel symptoms at this point When a person begins experiencing HIV symptoms, in what cycle is the virus? lytic this is when the virus begins destroying Helper T cells, and as the number of Helper T cells is depleted, the host s immune system is weakened and the person is said to have AIDS (acquired immune deficiency syndrome) j. Explain the purpose of vaccination as well as how a vaccine works How is a vaccine created?

5 a vaccine is a weakened version of the virus How do vaccines work? when it s injected into the body, it stimulates the body s own immune response against invasion by microbes. k. Describe the characteristics of archaea What are archaea? single-celled prokaryotes, typically live in extreme environments What are special features of archaea? Can withstand high temperature and high amounts of salt, and very acidic or very basic environments l. Compare and contrast the different types of bacteria What are obligate anaerobes? cannot live in the presence of oxygen (it s toxic to them) What are obligate aerobes? must have oxygen (O 2 ) to live What are facultative anaerobes? can live in the presence or absence of oxygen (O 2 ) How are bacteria and archaea similar? both are single-celled prokaryotes, both have pili, plasmids and flagella How are bacteria and archaea different? bacteria cell walls are made of peptidoglycan, archaea have membranes that are made of many different lipids m. Identify the structures of a bacterium (pili, nucleoid, flagella, etc.) Label the structure to the right. 1. plasmid 2. cell wall 3. chromosome 4. cell membrane 5. pili 6. flagella What is an endospore? An endospore is a thick-walled protective spore that forms inside a bacterial cell and resists harsh conditions What s the purpose of pili? to exchange genetic material between bacteria (in a process called conjugation)

6 n. Describe the two ways in which bacteria reproduce (binary fission and conjunction) Describe the process of binary fission. when a prokaryote divides into two cells (asexual reproduction) How does conjunction work? bacteria create a conjugation bridge between two bacterial cells so that the cells can exchange genetic material (sometimes referred to as bacterial sex ) o. Evaluate the economic, social, and medical significance of bacteria What are some beneficial roles that bacteria play in an organism? -populate our GI tracts to help us digest food -ferment certain foods such as yogurt, sauerkraut, and cheese -nitrogen fixation -bioremediation How are bacteria used to make some foods? fermented to form things like yogurt, cheese and sauerkraut What is nitrogen fixation and how are bacteria used in this process? Bacteria convert atmospheric nitrogen (N 2 ) into ammonia (NH 3 ) for plants to take up and use What is bioremediation? Using genetically engineered bacteria to decrease levels of pollutants (ex: using genetically engineered bacteria to clean up oil spills) What is antibiotic resistance? When antibiotics become less effective in killing bacteria because bacteria are becoming resistant to antibiotics Who is Alexander Fleming and what was his contribution to science? Scientist who discovered penicillin (first antibiotic) Why is antibiotic resistance bad? If bacteria become increasingly resistant to antibiotics, we will one day reach a point where doctors will not have anything to prescribe patients suffering from a bacterial infection.