Transduction

Transduction is the process whereby DNA is transferred between bacteria by packaging into a phage particle. Transduction begins when a phage that has infected a bacterium mistakenly packages a segment of the host cell’s chromosome into its capsid, or head, instead of its own DNA. The bacteriophage shown injects its DNA into a cell, where it is used to produce numerous new phage particles. Note that the front-most progeny phage being assembled in this cell internalizes a piece of the host’s DNA, shown as a white wavy line. When the cell lyses and releases the mature phage particles, the phage containing a portion of the bacterial chromosome proceeds to infect a new cell. This phage is called a transducing phage since it can transfer the genetic material of the first bacterium into the second. However, since no phage DNA enters the target cell, the bacterium does not produce phage or lyse. Instead, the infecting DNA may undergo a homologous recombination event with the bacterial chromosome, as shown. A single strand from each helix invades the other DNA molecule, resulting in phage-mediated transfer of genetic material from one bacterium to the other. This completes the general process of transduction.

Question 1: What is transduction?
  1. Transfer of cellular DNA by a phage particle
  2. Transfer of phage between bacterial cells
  3. Transfer of conjugative plasmid between cells
  4. Infection of a bacterial cell with phage


Answer 1

Answer - (a) Transfer of cellular DNA by a phage particle

Question 2: Transduction is when a phage that has infected a bacterium mistakenly packages a segment of the host cell's chromosome into its capsid instead of its own __________.
  1. RNA
  2. protein
  3. DNA
  4. mRNA


Answer 2

Answer - (c) DNA

Question 3: When the cell lyses and releases mature phage particles, some phages can contain a portion of _________ proceed to infect a new cell.
  1. the bacteriophage chromosome
  2. the eukaryotic chromosome
  3. the viral chromosome
  4. the bacterial chromosome


Answer 3

Answer - (d) the bacterial chromosome

Question 4: What is a phage that can transfer the genetic material from one bacterium to another called?
  1. transducing phage
  2. transfer phage
  3. transition phage
  4. viral phage


Answer 4

Answer - (a) transducing phage

Question 5: In transduction, instead of being used for producing phage what happens to the infecting DNA?
  1. It is ejected through the cell pore
  2. It is lysed
  3. It undergoes homologous recombination with the bacterial chromosome
  4. It is converted into RNA


Answer 5

Answer - (c) It undergoes homologous recombination with the bacterial chromosome