Midterm_review - Midterm review questions Chapter 23...

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Unformatted text preview: Midterm review questions Chapter 23 Post-test omit 8, 9, 12, 13, 14, 15, 18, 17 1. Pathogens a) are agents that cause disease 2. The genome of a virus consists of e) DNA or RNA 3. The capsid of a virus consists of a) protein 4. Viruses that kill host cells are b) lytic 5. The correct sequence in viral reproduction is c) attachment, penetration, replication, assembly, release 6. In lysogenic conversion a) bacterial cells may exhibit new properties 7. Peptidoglycan is a chemical compound found in the cell walls of d) most Eubacteria 10. In conjugation a) two bacterial cells of different mating types come together, and genetic material is transferred from one to another 11. Endospores b) are extremely durable cells 16. Prions c) appear to consist only of protein; no nucleic acid component has been found 19. Which group of bacteria contains the Gram-positive, anaerobic bacterium that causes botulism? A) clostridia What characteristics of life are absent in a virus? They are acellular, don’t carry on metabolic activity, reproduce only by taking over the reproductive machinery of other cells What are the steps in a lytic cycle? 1. Attachment(absorption): the phage attaches to the cell surface of a bacterium. 2. Penetration: Phage DNA enters the bacterial cell. 3. Replication: Phage DNA is replicated. Phage proteins are synthesized. 4. Assembly: Phage components are assembled into mature viruses. 5. Release: The bacterial cell lyses and releases many phages that can then infect other cells. How is a lysogenic cycle different form a lytic cycle? A lytic cycle is when the bacteria kills the host cell. A lysogenic cycle is when the host cell displays new properties due to the bacterial DNA. In what ways do prokaryotic cells differ from eukaryotic cells? Prokaryotes lack nucleus and other membrane bound organelles. Contrast viroids, prions, and viruses: Viroids – short RNA strand with no protein coat; tiny, naked infectious particle consisting only of nucleic acid; Prions – an infectious agent that consists only of protein; Viruses – tiny pathogen consisting of a core of nucleic acid usually encased in protein and capable of infecting living cells; a virus is characterized by total dependence on a living host; bigger than prions and viroids Chapter 24. Post-test do 1, 2, 3, 4, 7, 9, 11, 12 1. Which of the following is not true of the protists? A) They are unicellular, colonial, coenocytic, or simple multicellular organisms B) their cilia and flagella have 9 + 2 arrangement of microtubules C) they are prokaryotic, like the eubacteria and archaebacteria D) some are free-living, and some are endosymbionts E) most are aquatic and live in the ocean or in freshwater ponds 2. Amoebas move and obtain food by means of A) pseudopodia 3. Foraminiferans C) secrete many-chambered tests with pores through which cytoplasmic extensions project 4. Unicellular protists that are free-living or parasitic, move by means of flagella, and do not photosynthesize are called d) zooflagellates...
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This test prep was uploaded on 04/15/2008 for the course BIOL 111 taught by Professor Hernandez during the Spring '08 term at Abilene Christian University.

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Midterm_review - Midterm review questions Chapter 23...

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