PCB 3063-Test Bank for Chapter 9: Bacterial and Viral Genetic Systems

PCB 3063-Test Bank for Chapter 9: Bacterial and Viral Genetic Systems Bacterial mutants that require supplemental nutrients in their growth media are called a. autotrophs. b. heterotrophs. c. prototrophs. d. omnitrophs. e. auxotrophs. Answer: e Section: 9.1 Comprehension Question 2. Which of the following statements about nutritional requirement and growth of bacteria is NOT true? a. Culture media developed for bacteria must contain carbon source and essential elements for the survival of the bacteria. b. Auxotrophic mutants can grow on medium that lack carbon source because they can synthesize their own nutrients. c. Each bacterium has specific nutritional needs and conditions for successful cultivation. d. Prototrophic bacterial strains can grow on minimal media. e. The growth rate of bacteria on specific media can be assessed by the number and size of bacterial colonies. Answer: b Section: 9.1 Comprehension Question 3. Bacterial strains that can produce all the necessary compounds and therefore grow on minimal media are called a. autotrophs. b. heterotrophs. c. prototrophs. d. omnitrophs. e. auxotrophs. Answer: c Section: 9.1 Comprehension Question 4. Which of the following facts would NOT be considered as an advantage for using bacteria and viruses for genetic studies? a. Rapid reproduction and high progeny number b. Haploid genome for expressing mutations c. Complete absence of recombination, which maintains the integrity of genome d. Low cost to maintain and little storage space required e. Genomes being small and readily subjected to genetic manipulation Answer: c Section: 9.1 Comprehension Question 5. Which of the following statements about bacterial genome is NOT true? a. All bacteria contain a single circular double stranded DNA as their genome. b. Some bacteria may have linear chromosomes instead of circular one. c. In addition to chromosome, many bacteria possess small extrachromosomal DNA called plasmid. d. Each plasmid contains an origin of replication that allows independent replication for its maintenance. e. The F factor, which is important for bacterial conjugation is found as a circular episome of E.coli. Answer: a Section: 9.1 Comprehension Question 6. What is the result of conjugation between F’ and F– cells? a. One F+ cells b. Two F’ cells c. Two F+ cells d. One Hfr and one F– cells e. Two Hfr cells Answer: b Section: 9.1 Application Question 7. Bacterial cells containing an F plasmid that has acquired bacterial chromosomal genes are called a. F + . b. F′. c. F – . d. Hfr. Answer: b Section: 9.2 Comprehension Question 8. A bacterial cell transfers chromosomal genes to F– cells, but it rarely causes them to become F + . The bacterial cell is a. Hfr. b. lysogenic. c. auxtrophic. d. lytic. e. F + Answer: a Section: 9.2 Comprehension Question 9. Which of the following statements about genetic exchange in bacteria is NOT true? a. In some viruses, the DNA that encodes one gene product can overlap with DNA that encodes a different gene product. b. Plasmids do not have to integrate into the host cell chromosome in order to be replicated. c. Interrupted conjugation results in the production of Hfr strains. d. The order of gene transfer is not the same for different Hfr strains. e. Antibiotic resistance can be transferred from one bacterial cell to another by conjugation. Answer: c Section: 9.2 Comprehension Question 10. Which of the following will have the least influence on the efficiency of transformation in E. coli bacteria? a. Calcium chloride treatment b. Heat shock c. Electrical field d. Chilling on the ice e. The amount of foreign DNA Answer: d Section: 9.2 Comprehension Question 11. Which of the following horizontal gene transfer mechanisms would specifically use time as a basic unit of mapping? a. Transformation b. Crossing-over