13 This data was collected after a culture of E coli was initially exposed to different concentrations of different disinfectants Its ability to grow in the presence of each disinfectant is evaluated column initial The E coli is then subcultured into media that does not contain the disinfectant and its ability to grow after the disinfectant is removed is evaluated column subcultured Which of the following disinfectants exhibits ONLY bacteriocidal activity at all effective concentrations growth No growth Concentration 1 10 1 20 1 100 1 1000 1 5000 Initial Disinfectant 1 a Disinfectant 1 b Disinfectant 2 c Disinfectant 3 d Disinfectant 4 Subculture Initial Disinfectant 3 Disinfectant 2 Subculture Initial Subculture Initial Disinfectant 4 Subculture 14 Which of the following statements is TRUE regarding the control of microbial growth via irradiation a Irradiated foods are dangerous to consume and the FDA has banned them from being sold within the US b Exposure to UV gamma rays electron beams and X rays works causes damage to the cell s nucleic acids c Gamma radiation is the most effective way to neutralize prions d UV exposure has been shown to be extremely effective at penetrating surfaces 15 Which of the following statements is TRUE in regards to the stress induced toxin antitoxin system in E coli In this system MazE is the antitoxin and MazF is the toxin a Maze is synthesized continuously but MazF is synthesized only when the cell is under stress b Peptide fragments from G6PD will cleave mRNA and result in the cellular stasis c The stress response will result in the cell discontinuing synthesis of both MazE and MazF but the more stable MazF will persist in the cell for longer than MazE and can begin cleaving mRNA molecules d The stress response will result in the cell discontinuing synthesis of MazE but not MazF herefore MazF is free to begin cleaving mRNA molecules