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Biological Sciences

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Bacteria

Question
7 out of 7
 

Certain antibiotics work by inhibiting protein synthesis. However, proteins made before exposure to these drugs will continue to function until degraded by the cell. Which of the following would probably be true after adding these antibiotics to a culture of bacteria?

A DNA replication would not continue.
B Severely damaged flagella could not be repaired.
C New pili could be added to the bacteria.
D Damage to the glycocalyx would kill the bacterial cell.
Ans. B

DNA replication (response A) would probably continue to occur by utilizing preexisting enzymes. Damage to the glycocalxy (response D) would not necessarily mean the cell would die. However, production of new pili or repair of flagella (B and C) would almost certainly require protein synthesis and therefore could not occur in the presence of this type of antibiotic.

Bacteria Flashcard List

7 flashcards
1)
Interestingly, many, if not most, bacterial cells can communicate with other cells in the same species. The bacteria secrete proteins, and, once enough bacteria are present, the concentration of the proteins increases. A high concentration often triggers the bacteria to turn on other proteins so the colony can perform a function. For example, individuals who have impaired immune systems or who have the genetic disease cystic fibrosis (CF) are often infected by the respiratory bacterium, Pseudomonas aeruginosa. Only when enough bacteria have accumulated, P. aeruginosa will produce an enzyme that degrades lung tissue which allows the bacteria to invade the blood stream. Although many examples of this intraspecies communication exist, scientists wondered if different species can communicate with each other. To answer this question, researchers examined the relationship between P. aeruginosa and Burkholderiacepacia. B. cepacia causes fatal lung infections in CF patients, but only after these individuals have also been infected by P. aeruginosa. Experiment 1: P. aeruginosa were grown in an appropriate liquid medium in the laboratory. The culture was centrifuged to remove the bacterial cells. A culture of B. cepacia was then grown in the medium. These bacteria increased production of molecules necessary for survival. Experiment 2: Mutant P. aeruginosa were grown in the laboratory in liquid medium. After centrifugation, the medium was used to incubate cultures of B. cepacia. Very few “survival molecules” were produced in the B. cepacia. The experiments indicate:A The two bacterial strains can communicate with each otherB The P.aeruginosa bacteria help turn on production of survival molecules in B.cepaciaC B.cepacia bacteria help turn on production of survival molecules in P.aeruginosaD No communication exists between the two bacterial strains
2)
Interestingly, many, if not most, bacterial cells can communicate with other cells in the same species. The bacteria secrete proteins, and, once enough bacteria are present, the concentration of the proteins increases. A high concentration often triggers the bacteria to turn on other proteins so the colony can perform a function. For example, individuals who have impaired immune systems or who have the genetic disease cystic fibrosis (CF) are often infected by the respiratory bacterium, Pseudomonas aeruginosa. Only when enough bacteria have accumulated, P. aeruginosa will produce an enzyme that degrades lung tissue which allows the bacteria to invade the blood stream. Although many examples of this intraspecies communication exist, scientists wondered if different species can communicate with each other. To answer this question, researchers examined the relationship between P. aeruginosa and Burkholderiacepacia. B. cepacia causes fatal lung infections in CF patients, but only after these individuals have also been infected by P. aeruginosa. Experiment 1: P. aeruginosa were grown in an appropriate liquid medium in the laboratory. The culture was centrifuged to remove the bacterial cells. A culture of B. cepacia was then grown in the medium. These bacteria increased production of molecules necessary for survival. Experiment 2: Mutant P. aeruginosa were grown in the laboratory in liquid medium. After centrifugation, the medium was used to incubate cultures of B. cepacia. Very few “survival molecules” were produced in the B. cepacia. The key to communication between these two bacteria is probably due to:A A soluble protein secreted by P. aeruginosa.B Direct interaction between the two bacteria, possibly via cells of each species binding to each other.C A soluble protein secreted by B. cepacia.D Unable to determine based on the available data.
3)
Interestingly, many, if not most, bacterial cells can communicate with other cells in the same species. The bacteria secrete proteins, and, once enough bacteria are present, the concentration of the proteins increases. A high concentration often triggers the bacteria to turn on other proteins so the colony can perform a function. For example, individuals who have impaired immune systems or who have the genetic disease cystic fibrosis (CF) are often infected by the respiratory bacterium, Pseudomonas aeruginosa. Only when enough bacteria have accumulated, P. aeruginosa will produce an enzyme that degrades lung tissue which allows the bacteria to invade the blood stream. Although many examples of this intraspecies communication exist, scientists wondered if different species can communicate with each other. To answer this question, researchers examined the relationship between P. aeruginosa and Burkholderiacepacia. B. cepacia causes fatal lung infections in CF patients, but only after these individuals have also been infected by P. aeruginosa. Experiment 1: P. aeruginosa were grown in an appropriate liquid medium in the laboratory. The culture was centrifuged to remove the bacterial cells. A culture of B. cepacia was then grown in the medium. These bacteria increased production of molecules necessary for survival. Experiment 2: Mutant P. aeruginosa were grown in the laboratory in liquid medium. After centrifugation, the medium was used to incubate cultures of B. cepacia. Very few “survival molecules” were produced in the B. cepacia. A similar communication system exists between: I. Nerve cells II. Hormones and receptors III. Photoreceptors in the eyeA I onlyB II onlyC I and II onlyD III only
4)
Interestingly, many, if not most, bacterial cells can communicate with other cells in the same species. The bacteria secrete proteins, and, once enough bacteria are present, the concentration of the proteins increases. A high concentration often triggers the bacteria to turn on other proteins so the colony can perform a function. For example, individuals who have impaired immune systems or who have the genetic disease cystic fibrosis (CF) are often infected by the respiratory bacterium, Pseudomonas aeruginosa. Only when enough bacteria have accumulated, P. aeruginosa will produce an enzyme that degrades lung tissue which allows the bacteria to invade the blood stream. Although many examples of this intraspecies communication exist, scientists wondered if different species can communicate with each other. To answer this question, researchers examined the relationship between P. aeruginosa and Burkholderiacepacia. B. cepacia causes fatal lung infections in CF patients, but only after these individuals have also been infected by P. aeruginosa. Experiment 1: P. aeruginosa were grown in an appropriate liquid medium in the laboratory. The culture was centrifuged to remove the bacterial cells. A culture of B. cepacia was then grown in the medium. These bacteria increased production of molecules necessary for survival. Experiment 2: Mutant P. aeruginosa were grown in the laboratory in liquid medium. After centrifugation, the medium was used to incubate cultures of B. cepacia. Very few “survival molecules” were produced in the B. cepacia. One important control that should be included in this experiment is:A Grow P. aeruginosa in medium used to grow B. cepacia first.B Infect mice with both species of bacteria.C Grow B. cepacia in medium that had not been used to grow P. aeruginosaD No other control is necessary for this experiment.
5)
Interestingly, many, if not most, bacterial cells can communicate with other cells in the same species. The bacteria secrete proteins, and, once enough bacteria are present, the concentration of the proteins increases. A high concentration often triggers the bacteria to turn on other proteins so the colony can perform a function. For example, individuals who have impaired immune systems or who have the genetic disease cystic fibrosis (CF) are often infected by the respiratory bacterium, Pseudomonas aeruginosa. Only when enough bacteria have accumulated, P. aeruginosa will produce an enzyme that degrades lung tissue which allows the bacteria to invade the blood stream. Although many examples of this intraspecies communication exist, scientists wondered if different species can communicate with each other. To answer this question, researchers examined the relationship between P. aeruginosa and Burkholderiacepacia. B. cepacia causes fatal lung infections in CF patients, but only after these individuals have also been infected by P. aeruginosa. Experiment 1: P. aeruginosa were grown in an appropriate liquid medium in the laboratory. The culture was centrifuged to remove the bacterial cells. A culture of B. cepacia was then grown in the medium. These bacteria increased production of molecules necessary for survival. Experiment 2: Mutant P. aeruginosa were grown in the laboratory in liquid medium. After centrifugation, the medium was used to incubate cultures of B. cepacia. Very few “survival molecules” were produced in the B. cepacia. The mutant P. aeruginosa used in Experiment 2 were most likely deficient in:A ReplicationB TranscriptionC TranslationD Secretion
6)
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