Biology Multiple Choice, 2 pt each.

Transcription

1 Biology 3340 Spring 2007 Name Exam 1, Version A Write your name on both the exam booklet and the mark sense sheet. On the upper left corner of the mark sense sheet in the Key ID box, mark the version letter of your exam. If you don't, you may fail. Each question has one correct answer. When a group of choices is used for more than one question, a choice may be used more than once (you can't eliminate choices you've already used). You may not take phone calls, text messages, or any other communication during the test. To do so will immediately end your examination. You may not leave the room during the examination. Multiple Choice, 2 pt each. The following choices are used for questions 1 5. (a) Mass determination (b) Membrane filtration (c) Microscopic cell count (d) Serial dilution and colony counting (e) Turbidity 1. This method is best for determining the number of viable cells in a bacterial culture with a very high concentration. 2. This technique requires the use of a centrifuge. 3. This technique requires the use of a Petroff-Hausser counting chamber. 4. This technique requires the use of a vacuum source. 5. This technique requires the use of a spectrophotometer. 6. In a continuous culture (a) fresh broth is added to the culture at a constant rate. (b) the concentration of cells will typically reach an equilibrium level that remains constant as long as the nutrient feed is maintained. (c) growth is divided into lag stage, logarithmic stage, stationary stage,and death stage. 7. Which of the following is true about viruses? (a) All virus particles consist of a nucleic acid molecule, a capsid, and an envelope. (b) All virus particles contain both DNA and RNA. (c) All viruses replicate only within an infected host cell... 1

2 The following choices are used for questions (a) A medium with the following composition: 0.1% glucose, 0.05% potassium phosphate (ph 7.0), 0.02% magnesium sulfate, 0.01% iron (II) sulfate (b) A medium with the following composition: 0.01% glucose, 0.009% potassium phosphate (ph 7.0), % sodium citrate, % magnesium sulfate, 0.001% ammonium sulfate, 1.5% agar (c) Tryptic soy agar.. 8. Nitrogen fixing bacteria can use N 2 as a sole nitrogen source. Which medium could be used as a selective medium to enrich for nitrogen fixing bacteria while not allowing any other bacteria to grow? 9. Which medium is a chemically defined medium? 10. Which medium is a semisolid medium? The following choices are used for questions (a) ATP-binding cassette transporter systems (b) Cotransport systems (c) Group translocation systems 11. In this type of transport system, the target binds to a soluble protein in the periplasm of gramnegative bacteria. 12. In this type of transport system, the energy to transport one substance from a low to high concentration is provided by the simultaneous transport of another substance from a high to low concentration. 13. This type of system is used in the transport of ferric ions. 14. In this type of transport system, the hydrolysis of a high-energy phosphate compound provides both the energy for the transfer of the target as well as a phosphate group that becomes attached to the target. 15. In this type of transport system, the target is transported through the membrane with an ATPase pump. The following choices are used for questions (a) autotroph (b) auxotroph (c) chemotroph (d) heterotroph (e) lithotroph 16. This term refers to organisms that cannot use CO 2 as a carbon source, but require an organic source of carbon. 17. This term refers to organisms that can use an inorganic source of reduction potential. 2

3 18. Ribosomes found within the mitochondria of fungus cells (a) are more similar in size to the ribosomes found attached to the endoplasmic reticulum of algae cells than the ribosomes found within the ribosomes of protozoa. (b) are more similar in size to the ribosomes attached to the endoplasmic reticulum of oak cells than to the ribosomes found suspended in the cytoplasm of cat cells. (c) are more similar in size to the ribosomes found in Escherichia coli than to the ribosomes found attached to the endoplasmic reticulum of oak tree cells. (d) are more similar in size to the ribosomes found suspended in the cytoplasm of cat cells than the ribosomes found in Staphylococcus aureus. (e) are more similar in size to the ribosomes found suspended in the cytoplasm of cat cells than the ribosomes suspended in the cytoplasm of chloroplasts. 19. Which of the following conditions is adequate for killing bacterial spores in a liquid medium? (a) Autoclaving under pressure at 120 C for 30 min. (b) Boiling at 100 C for 30 min. (c) Heating to 70 C for 30 min. 20. Which of the following is true about the process of bacterial sporulation? (a) When a bacterial cell bursts at the end of sporulation, two free spores are released. (b) When a bacterial cell sporulates, there is an asymmetric septation of the plasma membrane and cell wall, with one copy of the chromosome in a large partition, and the other copy of the chromosome packed into a smaller partition. (c) When a bacterial cell sporulates, the chromosome is replicated... The following choices are used for questions (a) Archaea (b) Bacillus and Clostridium (c) Mycobacterium and Nocardia (d) Mycoplasma and Ureaplasma (e) Streptococcus pneumoniae 21. Prokaryote(s) that have cholesterol in their plasma membranes. 22. Prokaryote(s) that have high concentrations of mycolic acid in their cell walls. 23. Prokaryote(s) that have N-acetyltalosaminuronic acid in their cell walls. 24. Prokaryote(s) that have no cell walls. 25. Prokaryote(s) that can form bacterial endospores. 3

4 The following choices are used for questions (a) Braun s lipoprotein (b) hopanoid (c) mycolic acid (d) poly-β-hydroxybutyrate (e) siderophore 26. This substance, similar in structure to cholesterol, is found in the plasma membrane of many bacterial species. 27. This substance anchors the outer membrane to the peptidoglycan layer in gram-negative bacteria. 28. This substance is secreted by many bacteria to sequester ferric iron for subsequent transport. 29. This substance is a lipid that can form inclusions that are visible with a compound microscope in the cytoplasm of some bacteria. 30. This substance is a waxy lipid found in large amounts in the cell wall of acid-fast bacteria. 31. A typical gram positive cell wall contains (a) teichoic acid (b) peptidoglycan (c) porin 32. The O side chain polysaccharide (a) is attached to teichoic acid molecules. (b) varies in composition between different strains of bacteria, making it useful in the serological detection of those strains. (c) is responsible for indirect crosslinking in peptidoglycan. 33. The peptidoglycan in gram-negative bacteria (a) has direct peptide crosslinking but not indirect crosslinking. (b) forms a layer approximately nm thick. (c) is more extensively crosslinked than the peptidoglycan in gram-positive bacteria. 4

5 The following choices are used for questions (a) Koch (b) Lister (c) Pasteur (d) Semmelweis (e) Snow 34. He suggested that the incidence of infections in mothers after childbirth could be reduced if the attendants washed their hands before delivering the baby. 35. He developed antiseptic surgical procedures that used carbolic acid (phenol) as a disinfectant. 36. By using maps to localize the source of a cholera epidemic in London to a specific public water pump, he was able to reduce its spread by implementing public health measures. 37. He developed a vaccine for rabies. 38. Using colony isolation techniques on agar media, he isolated the anthrax and tuberculosis bacteria and demonstrated their roles in disease. The following choices are used for questions (a) coryneform (b) sarcina (c) spirillum (d) spirochete (e) vibrio 39. This term refers to bacteria with irregularly rod-shaped cells arranged at angles to form V- and L-shaped arrangements. 40. This term refers to bacteria with flexible, spiral-shaped cells, often appearing as helical or corkscrew-shaped with tapered ends. 41. Which of the following is characteristic of peptidoglycan structure? (a) Alternating units of N-acetylglucosamine and N-acetylmuramic acid (b) Peptide crosslinking between N-acetylmuramic acid units (c) Teichoic acid crosslinking between N-acetylglucosamine units 42. Which of the following is characteristic of bacterial capsules? (a) They are located within a specialized region of the cell s cytoplasm. (b) They are composed of polysaccharide or polypeptide. (c) They appear as clear halos surrounding cells in a negative stain. 5

6 43. A typical gram positive cell wall contains (a) porin (b) peptidoglycan (c) teichoic acid 44. Which of the following diagrams shows an erose margin? 45. Read each of the following three statements about bacterial colonies. I. Ideally, an isolated bacterial colony contains cells of only a single species. II. The morphology of a bacterial colony is a characteristic of the species. III. Bacterial colonies can be isolated by culturing the bacteria in tryptic soy broth. Which statement(s) is (are) true? (a) I, II, and III (b) I only (c) I and III only (d) I and II only (e) II and III only The following choices are used for questions (a) hopanoid (b) mycolic acid (c) peptidoglycan (d) siderophore (e) teichoic acid 46. 6

7