Bacterial Genetics Flashcards
How do complex transposons differ from simple transposons?
A: Complex transposons are found in multiple locations in the target DNA; simple transposons are found only in one location.
B: Complex transposons code for additional genetic elements, such as antibiotic resistance genes; simple transposons only code for the transposase gene essential for the tranposon itself.
C: Complex transposons code for transposase; simple transposons do not.
B
What is the difference between an F+ and an Hfr bacterium?
A: F+ bacteria have an F plasmid that includes some nuclear genes, while Hfr (high frequency recombinant) bacteria have an F plasmid with only the essential genes for conjugation.
B: F+ bacteria have a plasmid with only the essential genes for conjugation, while Hfr (high frequency recombinant) bacteria have an F plasmid that includes some nuclear genes.
C: F+ bacteria have an integrated F plasmid, while Hfr bacteria have a nonintegrated F plasmid.
D: F+ bacteria have a nonintegrated F plasmid, while Hfr bacteria have an F plasmid that is integrated into their main chromosome.
D
What must occur for bacterial conjugation to take place?
A: The cells must come into contact with each other.
B: One of the cells must be E. coli.
C: Each cell must contain a plasmid.
D: The cells must transfer RNA.
A
Which statement about conjugation is false?
A: E. coli is the model for bacterial conjugation.
B: After conjugation, each cell involved has a copy of the shared DNA.
C: Conjugation is a process of bacterial reproduction.
C
What is unique about transduction compared to normal bacteriophage infection?
A: The bacteriophage does not erupt from an infected cell during transduction.
B: The bacteriophage takes fragments of the cell with it during transduction.
C: Transduction transfers DNA from the chromosome of one cell to another.
C
How is generalized transduction different from specialized transduction?
A: Only one specific host gene is transferred in both specialized transduction and generalized transduction.
B: Generalized transduction is initiated by a lysogenic bacteriophage; specialized transduction is initiated by a lytic phage.
C: Specialized transduction uses animal viruses instead of bacteriophage.
D: Generalized transduction is initiated during lytic cycle of a virulent bacteriophage; specialized transduction is initiated during the lysogenic cycle of a temperate bacteriophage.
D
A transducing phage
A: is a lysogenic bacteriophage.
B: cannot infect new host cells.
C: has a viral coat made of host proteins.
D: contains fragments of the host chromosome instead of the viral genome.
D
During conjugation, if an Hfr cell is mated with an F- cell, why will the F- cell remain F-?
A: The cells would not stay in contact long enough for the entire Hfr genome to be transferred.
B: The recipient will not remain F-, it will become F+.
C: The donor cell is not an F+ cell, it is Hfr.
D: The recipient will not remain F-, it will become Hfr because of the donor cell genome.
A
How do restriction enzymes cut DNA sequences?
A: They have the ability to cut DNA randomly.
B: They cut DNA at sites, called recognition sites, that have specific nucleotide sequences.
C: They cut DNA at sequences that have lots of adenine bases.
B
In general, how might recombinant DNA technology be used to prevent a genetic disorder caused by a mutation in a single gene?
A: To insert a desirable gene, remove an undesirable gene, or replace a defective gene with a functioning gene
B: To insert a desirable gene
C: To replace a defective gene with a working gene
D: To remove an undesirable gene
A
Which of the following attaches the target gene to a desired location? A Chromosomal DNA B Restriction enzymes C Plasmids D DNA ligase
D
Why would a recombinant DNA molecule be inserted into a host cell?
A: Restriction enzymes can only be used inside of a cell.
B: It can be copied, transcribed, and translated into a desired protein.
C: It can protect the recombinant DNA.
D: Plasmids cannot be isolated outside of a host cell.
B
Which process listed below does NOT require homologous recombination to maintain the new genetic material in the recipient cell?
A transduction by a dsDNA phage Mu
B conjugation of a linear piece of DNA
C transformation of a linear piece of DNA
D gene transfer through a genetic transfer agent
D
Which of the following proteins is NOT required for homologous recombination? A Hfr B endonuclease C proteins having helicase activity D RecA
A
Consider the following experiment. First, large populations of two mutant strains of Escherichia coli are mixed, each requiring a different, single amino acid. After plating them onto a minimal medium, 45 colonies grew. Which of the following may explain this result?
A The colonies may be due to recombination.
B The colonies could be due to either recombination or back mutation.
C The colonies may be due to back mutation (reversion).
D The colonies being due to recombination or back mutation is not possible.
B
Homologous recombination has been observed in A Archaea, Bacteria, and Eukarya. B Eukarya. C Bacteria. D Archaea.
A
A deleterious mutation in recA results in
A an increase in homologous recombination.
B no change in either general or specific recombination.
C a decrease in specific recombination.
D a decrease in homologous recombination.
D
recA is involved in DNA repair and homologous recombination
The process in which related DNA sequences from two different sources are exchanged is called A homologous recombination. B transduction. C phage conversion. D reversion.
A
Mice that are injected with only the R strain of Streptococcus pneumoniae
A stay healthy, because their immune systems can kill this strain easily.
B become sick for prolonged periods of time.
C are killed, because R strain cells are deadly.
A
What characteristic of the S strain allows it to evade the immune system of the mice?
A The cells have a capsule.
B They are resistant to heat.
C They are genetically engineered to be resistant to killing.
D They are naturally competent.
A
What most likely explains the recovery of live S strain cells from a mouse injected with heat-killed S strain mixed with live R strain cells?
A The R strain cells picked up the capsules from the S strain cells.
B The R strain picked up the S strain DNA, enabling it to produce a capsule.
C The S strain fused with the R strain, making it resistant.
D The S strain was revived by the presence of the host’s immune system.
B
Which finding is most surprising from Griffith’s experiments?
A S strain cells kill the mice.
B S strains are able to escape phagocytosis.
C S strain cells are isolated from the blood of mice infected with heat-killed S strains and live R strains.
D R strain cells fail to produce a capsule.
C