B) design and insert CRISPR spacer sequences into the genomes of your strains that are complementary to the genomes of the phages that are infecting the cultures.

Hfr means high frequency of ________, and these cells are capable of transferring genes from their ________ to other cells. A) transformation / chromosome B) transduction / plasmids C) recombination / chromosome D) transduction / chromosome

C) recombination / chromosome

Mutation rates are similar in Bacteria and Archaea, yet certain stressful conditions mutation rates increase. Why is the mutation rate not constant and close to zero all of the time? A) Increased mutation rates can be advantageous in rapidly changing environments because some random mutations may be useful for survival. B) Microorganisms carefully control the mutation rate of their DNA to match the environmental conditions and maximize evolution. C) The increased mutation rate under stressful conditions is an indication that the microorganisms can no longer replicate their DNA properly and are about to die. D) Constant mutation rates would halt evolution completely.

A) Increased mutation rates can be advantageous in rapidly changing environments because some random mutations may be useful for survival.

Chemical mutagens, UV radiation, and ionizing radiation all increase mutation rates, but they have different mechanisms. Which type of mutagen would be best suited for creating large deletions and rearrangements within a genome? A) chemical mutagens B) UV radiation C) ionizing radiation D) Chemical, UV, and ionizing radiation would create large deletions and rearrangements if used in a very high dose.

C) ionizing radiation

) The SOS system repairs DNA that has gaps, breaks, and other lesions by A) cutting DNA from other parts of the genome and pasting it into the gaps or damaged areas. B) stabilizing single-stranded DNA until the next round of normal replication. C) using specialized DNA polymerases that will synthesize a new DNA strand even if there is not a normal complementary DNA strand to act as a template. D) using available mRNA and a special RNA-dependent DNA polymerase to fill in the gaps and replace damaged DNA.

C) using specialized DNA polymerases that will synthesize a new DNA strand even if there is not a normal complementary DNA strand to act as a template.

Microinsertions and microdeletions often result in ________ mutations. A) auxotrophic B) advantageous C) silent D) frameshift

D) frameshift

When damaged or single-stranded DNA activates the RecA protein, the RecA protein stimulates the cleavage of LexA. This results in A) repression of polymerase V and activation of endonuclease. B) activation of the Hfr system. C) derepression of the SOS system. D) increased transduction and recombination.

C) derepression of the SOS system.

The F (fertility) plasmid contains a set of genes that encode for the ________ proteins that are essential in conjugative transfer of DNA. A) pili B) SOS repair C) transduction D) transformation

A) pili

The designations Phe-, Leu-, and Ser+ refer to an organism's A) plasmid type. B) genotype. C) phenotype. D) mutation type.

C) phenotype.

If a bacterium carrying a plasmid that confers resistance to ampicillin is placed into medium without ampicillin, it may A) gain resistance to other antibiotics. B) transfer resistance to other cultures in the laboratory. C) undergo a reversion mutation. D) lose the plasmid because there is no selection for ampicillin resistance.

D) lose the plasmid because there is no selection for ampicillin resistance.

When DNA is transferred into a prokaryotic cell it may A) be degraded by enzymes. B) replicate independent of the host chromosome. C) recombine with the host chromosome. D) be degraded by enzymes, replicate independent of the host chromosome, or recombine with the host chromosome.

D) be degraded by enzymes, replicate independent of the host chromosome, or recombine with the host chromosome.