Exam 16: Mechanisms of Genetic Variation

SOS repair

Transformation has been observed in only a limited number of species in nature,but we have found ways to force the process upon other species in the laboratory.

The genome of a recipient cell is called a(n)__________.

An F' plasmid results when

Mutations that result in the death of an organism when expressed are called __________ mutations.

Which of the following is true of the integration of a viral genome into the host chromosome?

Photoreactivation repairs thymine dimers by splitting them back into separate thymines.

When an F' plasmid acts as the donor in a mating,which of the following do(es)not happen?

Transposable elements have been found only in prokaryotes and do not appear to play a major role in eukaryotes.

The transformation frequency of very competent cells is about 10^-6,or about 1 in 1,000,000 when an excess of DNA is used.

A recipient cell that is temporarily diploid for a portion of the genome during the replacement process is called a(n)__________.

Repair of an apurinic or apyrimidinic site in DNA by AP endonuclease must be completed by the action of

Who is credited with demonstrating unidirectional and nonreciprocal transfer of DNA between two mating

When an F plasmid integrates into the host chromosome,the strain is referred to as

In an F⁺ $\times$ F^- conjugation,the donor is the __________ strain.

As the result of exposure to a mutagen,cytosine is substituted for thymine in one strand of DNA.Upon subsequent DNA replication,one of the daughter cells will have a GC pair in this position instead of an AT pair.This is called a(n)__________ mutation.

When bacterial genes are transferred to another bacterium by a virus,it is called

Which of the following is considered a reverse mutation that will restore the wild type phenotype?

Spontaneous mutations are caused by

In order to take up a naked DNA molecule,a cell must be __________,which may occur only at certain stages in the life cycle of the organism.