Exam 10: Genetics of Bacteria and Arachaea

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 cellular mechanism, known as the ________, is activated because of DNA damage and initiates a number of DNA repair processes.

The appropriate designation for the phenotype of a histidine- requiring strain of Escherichia coli would be________ .

It is likely that lysogeny has a selective advantage in nature.

F+ strains of Escherichia coli

In generalized transduction, virtually any genetic marker can be transferred from donor to recipient at a high frequency. This process may occur with either a temperate or a virulent phage.

A(n)________ is a set of genes or operons that are all under the control of a particular type of _________ .

Microinsertions and microdeletions often result in ________mutations.

Use an example to describe the basis of the penicillin- selection method and why it is used.

Of the transposons that are now widely used, Tn5 and Tn10 carry antibiotic resistance markers to select for mutants.

The positions of genes on a genetic map are marked according to

The uptake of DNA released from a cell would most likely be the result of __________ , while cell- to- cell contact would most likely result in_________ .

How might mutations in the dnaQ sequence, whose enzyme is involved in DNA proofreading, be beneficial for a microbe in the environment?

F- strains of Escherichia coli

Which of the following is most similar to lysogeny?

The killing of cells by UV irradiation involves

Which of the following features are common to transformation, transduction, and conjugation? (1) unidirectional transfer of genes (2) incomplete gene transfer (3) homologous recombination (4) meiosis occurring in the recipient

Homologous recombination has been observed in

Called "crossing over" in classical genetics, the process in which DNA sequences are exchanged is now more commonly termed________ .

Transformation and homologous recombination allow for the formation of heteroduplex DNA. Which of the following would occur during DNA replication of this molecule?