Chapter 8 Bacterial Genetics Mutations and Repair Connect

A missense mutation has a greater impact on a cell than does a frameshift mutation.

False

Transposons are composed of amino acids.

False

Which of the following statements about the Ames test is FALSE?

Liver extract is added to provide nutrients.

Match the mutation with the correct name. Not all labels are used.

Synonymous mutation Missense mutation Nonsense mutation

Cells that are capable of bringing DNA from their environment into the cell through their cell wall are called:

competent.

Horizontal gene transfer can occur via

conjugation

In addition to transformation, the other two forms of horizontal gene transfer are

conjugation and transduction.

The first step in conjugation is:

contact between the donor

The first step in conjugation is

contact between the donor and recipient.

Transformation is a form of horizontal gene transfer that involves homologous recombination. Homologous recombination is

genetic recombination between similar or identical nucleotide sequences.

The classic transformation experiment done by Griffith used

harmless and virulent strains of Streptococcus pneumoniae.

F+ cells

have a plasmid and are donors in conjugation.

Genes from the donor chromosome are transferred as

single-stranded DNA

During conjugation, the donor chromosome is transferred as

single-stranded DNA.

UV light and other non-ionizing radiation damage DNA molecules by

creating thymine dimers between adjacent thymine nucleobases in the DNA chain.

Bacterial cells that have been genetically modified to carry an antibiotic resistance gene can be separated from susceptible (non-resistant) microbes by using a _______ selection method using agar plates with antibiotic.

direct

You are analyzing a bacterial genome. You find that the G-C content is 60%. However, in one part of the genome, the G-C content is 37%. What can you conclude?

The organism has a genomic island.

The F plasmid encodes for:

the F-pilus

These dimers are repaired by

the enzyme DNA photolyase and exposure to light.

After the conjugation of an Hfr cell with an F- cell

the recipient remains F-.

The main advantage for bacteria that have the ability to carry out conjugation and other forms of genetic exchange is that

they become genetically diverse.

A transposon can move from the host chromosomal DNA to a plasmid.

true

Transposons can cause mutations by

"jumping" into a gene and disrupting its function.

Which of the following statements is/are TRUE?

-Wild type E. coli must be provided with the amino acid histidine in order to grow. -A missense mutation will have greater consequence than a frameshift mutation.

Two bacterial genes are transduced simultaneously. What does this suggest about the location of the two genes relative to each other?

The two genes must be close together on the bacterial chromosome.

Preventing the function of light repair (photoreactivation) interferes with the repair of which of the following?

Thymine dimers

Which of the following requires that cells be competent?

Transformation

Generalized transduction occurs when

a bacteriophage packages a piece of bacterial DNA during replication.

During maturation or formation of phage particles,

a few phage heads may surround fragments of host bacterial DNA.

The F pilus is

a protein appendage that attaches the two cells together.

The F pilus is:

a protein appendage that attaches the two cells.

Plasmids are

able to replicate independently of the chromosome

Plasmids are:

able to replicate independently of the chromosome

Hfr refers to a cell that has

integrated the F plasmid into its genome.

In transduction, bacterial DNA is transferred to a new cell when

it is injected by the virus carrying bacterial DNA.

During the process of transformation in the lab setting, cells are plated on selective media to #42

make sure that only transformants grow.

If Gene X codes for an F pilus and transposition occurs, then the bacterium containing the plasmid would

no longer be able to conjugate

During the entry of the donor DNA into the recipient cell,

one strand is broken down by nucleases.

A recombinant organism is

one that contains genes from another organism

A recombinant organism is:

one that that contains genes from another organism.

Bacteriophages adsorb or attach

only to members of the same bacterial species.

The donor DNA

pairs with a homologous region of the recipient DNA.

After host cell DNA is broken down by a viral enzyme,

phage DNA is replicated and phage coat proteins are produced.

A difference between transferring plasmids and DNA fragments between bacterial cells is

plasmids can replicate independently.

Transformation is facilitated by

proteins on the cell wall that bind DNA from the environment.

Which of the following statements is TRUE?

A prototroph can grow on glucose-salts media.

Place the following events in the process of virus replication and the generation of a transducing particle in the correct order.

-A bacteriophage attaches to a specific receptor on a host cell -phage DNA enters the bacterial cell. the empty phage coat remains outside the host cell -Enzymes coded for by the phage cut the bacterial DNA into small pieces -Phage nucleic acid is replicated and coat proteins are synthesized -during virus assembly, bacterial DNA can sometimes mistakenly be packaged in the protein coat, creating a transducing particle

Place the following events in the process of transduction in the correct order. Not all labels are used.

1. a transfusing particle attaches to a specific receptor on a host cell 2. bacterial DNA is injected into a cell 3. foreign bacterial DNA integrates into the host genome by homologous recombination 4. bacteria multiply with new genetic material

Repair mechanisms that occur during DNA synthesis are

1. mismatch repair 2. proofreading by DNA polymerase

Consider the figure below. Which statement is TRUE?

5-bromouracil may be incorporated into a newly synthesized DNA strand in place of a thymine nucleobase.

On which of the following DNA strands will UV light have the most effect?

ACTTGCTTAC

Which of the following genes are likely to be found on a plasmid rather than on the bacterial chromosome?

ATP synthase gene Superoxide dismutase gene

Examples of advantageous genes that can be transferred by transduction are genes for -sugar fermentation. -toxin production. -drug resistance. -only drug resistance and toxin production.

All of the choices are correct.

In direct selection methods used to identify possible carcinogens (example: Ames testing), what does it mean when a chemical can cause a bacterium to develop resistance to some environmental condition?

The chemical is a mutagen.

Which of the following best describes vertical gene transfer?

Duplicating the entire genome and passing a copy to a daughter cell.

All mutagens are carcinogens but not all carcinogens are mutagens.

False

Chemical agents can cause mutations by inducing ethylation of guanine residues in DNA.

False

The entire genome of the donor cell is usually transferred to the recipient cell.

False

The enzyme ethylguanine-DNA ethyltransferase prevents DNA mutations from occurring.

False

Please match each mobile genetic element with its characteristic.

Plasmid-Generally encodes only non-essential genetic information. Transposon-DNA sequence that moves from one place to another in a genome. Genomic island-DNA segment in a cell's genome that originated in another species. Phage DNA-Virus genome that sometimes carries additional genes.

The plasmid is mobilized for transfer when

an endonuclease cleaves it at the origin of transfer.

The basic parts of a bacteriophage are

an icosohedral head, tail, tail pins, and fibers.

Mismatch repair is activated by

any difference between the nucleotide sequence in the donor and recipient DNAs.

A virus that infects bacterial cells is called a ______.

bacteriophage

After entry of the bacteriophage into the host cell, a phage enzyme

breaks the host DNA into fragments.

When the bacteriophage transfers bacterial DNA into a recipient bacterial cell, that DNA

can integrate into the chromosome.

As a result of mismatch repair during transformation:

cells may have either original DNA or donor DNA in them.

In the beginning of transformation, ______ binds to the target cell.

double-stranded DNA

A culture of E. coli is irradiated with UV light. The UV light affects the cell's DNA by

forming covalent bonds between thymine bases on the same strand of DNA.

F+ cells:

have a plasmid and are donors in conjugation.

What process involves the transfer of DNA from one bacterial cell to another via a sex pilus?

horizontal gene transfer by conjugation

Match the following key terms to refresh yourself with the concepts of Chapter 8: Bacterial Genetics.

https://gyazo.com/e0436e842c30a0e3a979e6c704224bbd

These dimers weaken ______ between bases.

hydrogen bonds

Plasmid DNA is transferred

in single-stranded form.

Plasmid DNA is transferred:

in single-stranded form.

If you find that a particular plasmid has an R factor, the bacteria that has it will be:

resistant to antibiotics.

If you find that a particular plasmid has an R factor, the bacteria that has it will be

resistant to certain antibiotics.

Transposons are

segments of DNA

Genes from the donor chromosome are transferred as

single-stranded DNA.

In transformation, genes from a donor chromosome are transferred as

single-stranded DNA.

The F pilus binds to

specific receptors on the cell wall of the recipient.

The F pilus binds to:

specific receptors on the cell wall of the recipient.

The F plasmid encodes for

the F pilus

F+ refers to a cell containing

the F plasmid

After the transfer of the F plasmid is complete

the F- cell becomes F+.

After the transfer of the F plasmid is complete:

the F- cell becomes F+.