Block One Text 10

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Block One Text 10
2014-09-28 12:48:46
Test One
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  1. a.       Exchange of genes between two DNA molecules to form new combos of genes on a chromosome
                                                                              i.      If a cell picks up foreign DNA, some of it can be inserted into cell’s chromosome by __--> __
    crossing over--> the DNA has recombined
  2. a.       Genetic recombination in bacteria can occur in many ways
                                                                              i.      Vertical gene transfer: __
                                                                            ii.      Horizontal gene transfer: __
    1.       Transfer involves __ and __ cell
    a.       Part of donor’s DNA is __and the remainder is __
    • occurs when genes are passed from organism to offspring
    • passing genes on laterally to other microbes
    • donor and recipient
    • incorporated into recipient’s DNA 
    • degraded
  3.                                                                           i.      Transformation: __
    genes are transferred from one bacterium to another as naked DNA in solution
  4.                                                                           i.      A protein called __binds to the cell’s DNA and then to donor DNA causing the __
    1.        A recipient cell with this new combo of genes is a kind of __; all descendants will be identical to it
                                                                            ii.      When a recipient cell is in a physiological state in which it can take up the donor DNA, it is __, which results from __
    • RecA 
    • exchange of strands
    • hybrid, or recombinant cell
    • competent
    • alterations in cell wall that make it permeable to large DNA molecules
  5. a.       Conjugation in Bacteria
                                                                              i.      Mediated by one kind of __, a circular piece of DNA that replicates independently from the cell’s chromosome
                                                                            ii.      Differ from bacterial chromosomes in that the genes they carry are __
    1.       Plasmids responsible for conjugation are __ between __ during __
    • plasmid
    • usually not essential for the growth of the cell under normal conditions
    • transmissible between cells during conjugation
  6.                                                                           i.      Different from transformation:
    1.       Requires __
    2.       Conjugating cells must be of __; donor cells must carry the __, and recipient cells usually don’t
    a.       Gram negative have __
    b.      Gram positive bacteria secrete __
    • direct cell to cell contact
    • opposite mating type
    • plasmid
    • plasmid carrying genes coding for synthesis of sex pili
    • sticky surface molecules
  7.                                                                           i.      In the process of conjugation, the plasmid is __during the transfer of a __ to the recipient, where the complementary strand is synthesized
    • replicated 
    • single-stranded copy of the plasmid DNA
  8.                                                                           i.      Process:
    • 1.       F factor (fertility factor) observed to be transferred between cells during conjugation (donors transfer them to recipients)
    • a.       In some cells carrying F factors, the factor integrates into the chromosome, converting the F+ factor cell to an Hfr cell
    •                                                                                                                                                   i.      When conjugation occurs between an Hfr cell and an F- cell, the Hfr cell’s chromosome replicates, and a parental strand of the chromosome is transferred tot eh recipient cell 
  9. a.       Replication of the __ begins in the middle of the __, and a small piece of the __ leads the chromosomal genes into the __
                                                                                                                                                      i.      Usually, chromosome __before completely transferred
                                                                                                                                                    ii.      Once in recipient cell, donor DNA can __, which allows F- cell to acquire new versions of chromosomal genes
    • Hfr chromosome
    • integrated F factor
    • F factor
    • F- cell
    • breaks 
    • recombine with recipient’s DDNA
  10. a.       Transduction in Bacteria
                                                                              i.      Bacterial DNA is transferred from a donor cell to a recipient cell inside __ that __
    a virus that infects bacteria, called a bacteriophage
  11. Generalized Transduction versus Specific Transduction
    •                                                                           i.      Generalized transduction:
    • 1.       During phase reproduction, phage DNA and proteins are made, which is not packaged inside the phage protein coat
    • a.       Bacterial DNA, plasmid DNA, and DNA of other viruses is inside the phage protein coat
    •                                                                         ii.      Specialized transduction: only certain bacterial cells are transferred
  12. a.       Plasmids and Transposons
                                                                              i.      Both are genetic elements that __
                                                                            ii.      Plasmids: __
    • provide additional mechanisms for genetic change
    • self-replicating, gene-containing circular pieces of DNA about 1-5% the size of the bacterial chromosome
  13. 1.       The F factor is a __ that carries genes for __ and for the __ 
    a.       Genes carried by plasmids can be crucial to the survival and growth of the cell 
    • conjugative plasmid
    • sex pili
    • transfer of the plasmid to another cell
  14.                                                                                                                                                   i.      __: code for enzymes that trigger the catabolism of certain unusual sugars and hydrocarbons
                                                                                                                                                    ii.      Others code for proteins that enhance the __of a bacterium
                                                                                                                                                  iii.      Still, other plasmids contain genes for the synthesis of __, toxic proteins that kill other bacteria
    • Dissimilation plasmids
    • pathogenicity 
    • bacteriocins
  15. 1.       Resistance factors (R factors) are __
    a.       Carry genes that __
    • plasmids that have significant medical importance
    • confer upon their host cell resistance to antibiotics, heavy metals, or cellular toxins
  16. a.       Contain two groups of genes:
                                                                                                                                                      i.      __ and includes genes for __ and __
                                                                                                                                                    ii.      __ has the __genes; codes for the production of __ that __
    b.      R factors present serious problems for treating infectious diseases with antibiotics; there are several resistant bacteria
    • Resistance transfer factor (RTF)
    • plasmid replication and conjugation
    • R-determinant
    • resistance 
    • enzymes that inactivate certain drugs or toxic substances