chapter 8
In conjugation, transformation, or transduction, the recipient bacteria is most likely to accept donor DNA
from the same species of bacteria.
The genetic makeup of the organism—in other words, the DNA sequence.
genotype
Genetic change in bacteria occurs through which two mechanisms?
horizontal gene transfer mutation
A mutation that changes a codon that specifies an amino acid to a stop codon, resulting in premature termination of polypeptide synthesis.
nonsense mutation
All mutagens are carcinogens but not all carcinogens are mutagens.
true
are DNA segments that increase the rate of mutations by inserting themselves into genes and inactivating them.
Blank 1: Transposons
The technique of colony------uses probes to detect specific DNA sequences in colonies grown on agar plates.
Blank 1: amino Blank 2: acid
Chemical mutagens can cause two types of mutations:----substitutions and-----mutations.
Blank 1: base, base pair, or nucleobase Blank 2: frameshift
Mutant cells in bacterial cultures can be isolated by-----selection and------selection methods.
Blank 1: direct Blank 2: indirect
Mutant cells in bacterial cultures can be isolated by----selection and-----selection methods.
Blank 1: direct Blank 2: indirect
Highly automated methods that generate huge amounts of DNA sequence data relatively quickly are termed-------- -----(or next-generation) sequencing.
Blank 1: high Blank 2: throughput
----------gene transfer, DNA moves from one organism to another, while in------- gene transfer, DNA is passed from a parent cell to its progeny.
Blank 1: horizontal Blank 2: vertical
A probe can be used to "find" a sequence of interest because it will anneal to its complement in a process called .
Blank 1: hybridization or annealing
is a change in the nucleotide sequence of DNA that is passed on to daughter cells.
Blank 1: mutation
Repair of nucleotide incorporation errors during the process of DNA replication is accomplished by-----by DNA polymerase and by-----repair.
Blank 1: proofreading Blank 2: mismatch
A laboratory technique used to determine the specific order of nucleotides in DNA is called DNA
Blank 1: sequencing
Mutations that arise naturally during cellular metabolism, and not as a result of exposure to mutation-causing agents, are called
Blank 1: spontaneous mutation
The most common type of mutation is base---where an incorrect nucleotide is incorporated during DNA replication.
Blank 1: substitution
In prokaryotes, genes can be transferred from a donor to a recipient via three different mechanisms:
Blank 1: transformation, bacterial transformation, or DNA-mediated transformation Blank 2: transduction Blank 3: conjugation
True or false: Ultraviolet rays are chemical mutagens.
False
_______ is used to determine which visible mass of bacterial growth on an agar plate contains a given DNA sequence.
colony blotting
Which of the following are the three main methods of gene transfer in bacteria?
conjugation transformation transduction
A plasmid that can directs its own transfer from donor to recipient cells is called a(n)------plasmid
conjugative
In order for insertional inactivation to occur, the transposon must be placed
within the gene in question.
A mutation that changes a codon into a different codon, but both codons specify the same amino acid; this causes no change in the resulting polypeptide.
synonymous mutation
The consequences of not repairing damaged DNA in cells include ______
cancer (in animals) cell death
The first step in a polymerase chain reaction (PCR) cycle requires a high temperature to _______.
denature the DNA double helix
Bacteria that have properties of both the donor and recipient cells are the result of
genetic recombination.
A large segment of a cell's genome that originated in other species is called a(n) ______.
genomic island
Mutants that can grow under conditions in which the parent (wild type) cells cannot are easily isolated by---selection
Blank 1: direct or positive
mutation results from an insertion or deletion of nucleotides, leading to a shift of the reading frame from the point of mutation downstream.
Blank 1: frameshift
Organisms most fit to survive in a given environment will predominate because they can reproduce more rapidly than others. This phenomenon is called
Blank 1: natural Blank 2: selection
The mechanism by which bacterial DNA is moved from one bacterium to another by a bacteriophage is called------
Blank 1: transduction
Segments of DNA that can move to new positions within the genome of a single cell are called
Blank 1: transposons
True or false: Vertical gene transfer is the transfer of genes from one organism to another in a population, while horizontal gene transfer is the transfer of genes from parent cell to progeny.
False
Which of the following statements about spontaneous mutation is TRUE?
If the mutation rate to antibiotic A is 10-9 per cell division, and to antibiotic B is 10-6 per cell division, the probability of the cell being resistant to both medications is 10-15.
CRISPR-Cas system
Insertion of small fragments of phage genome into host chromosome, giving the cell a "memory" of previous attempted infection and a way to recognize and destroy that foreign DNA in the future.
An origin of transfer is encoded by _______.
both conjugative and mobilizable plasmids
X-rays
cause breaks in DNA molecules.
A bacterial cell described as--------can take up DNA from the surrounding environment.
competent
Not all bacteria can take up DNA from the environment. Those that can are referred to as
competent.
The F or fertility plasmid contains genes that are required for bacterial ______.
conjugation
The genes that are present in all strains of a given species are called the ______.
core genome
A mutation that results in changing a codon such that a different amino acid is specified.
missense mutation
Preventing phage attachment.
Changing or covering up the molecules on the surface of the bacterium to which the phage particle binds.
Cells that have the ability to take up DNA from the environment are called ______ cells.
competent
Chemical mutagens often act by altering the
hydrogen bonding properties of the nitrogen bases
Chemicals that cause cancer are known as ______, and most of them are ______.
carcinogens; mutagens
is a large segment of a cell's genome that has clearly originated in a different species.
genomic islands
True or false: A point mutation always leads to a shift of the reading frame from the point of mutation downstream
False
True or false: A point mutation always leads to a shift of the reading frame from the point of mutation downstream. True false question.
False
When an excision errors produces a plasmid containing both chromosomal and F plasmid DNA, the resulting plasmid is called a(n)------plasmid.
Blank 1: F' or F prime
When an excision errors produces a plasmid containing both chromosomal and F plasmid DNA, the resulting plasmid is called a(n-----plasmid.
Blank 1: F' or F prime
"Jumping genes," or-----can move within a cell without specificity as to where they ultimately insert.
Blank 1: transposons
Which of the following are systems bacteria can use to protect against invading DNA?
CRISPR restriction-modification
Which of the following plasmids encodes all the necessary genetic information for transfer from one bacterial cell to another?
Conjugative plasmids only
During repair of oxidized guanine, which enzyme removes the damaged nucleobase from the sugar-phosphate backbone?
DNA glycosylase
Which of the following are needed for the polymerase chain reaction (PCR)?
DNA polymerase from Thermus aquaticus template DNA deoxynucleotides primers
_______ are single-stranded pieces of DNA, labeled with a detectable marker, used to locate specific complementary nucleotide sequences in nucleic samples attached to a solid surface.
DNA probes
In humans, two of the genes associated with the development breast cancer encode enzymes involved in ______.
DNA repair
When integrated F plasmid DNA in an Hfr cell is excised from the chromosome, an excision error can result in the removal of chromosomal DNA along with the F plasmid DNA, creating a plasmid called ______.
F'
______ plasmids encode resistance to a variety of antimicrobial agents and heavy metals.
R
_____ repair is activated by extensive DNA damage and uses a polymerase that lacks proofreading ability, ultimately resulting in mutations.
SOS
Why did the NIH form the Recombinant Advisory Committee?
To provide guidelines for researchers performing genetic engineering.
Which mechanism of gene transfer involves the uptake of "naked" DNA by competent bacterial reciarpient cells?
Transformation
The study of the crown gall tumor found
a bacterial plasmid promoter that was similar to plant promoters.
In conjugation in E. coli, an Hfr cell refers to ______.
a cell in which the F plasmid has been integrated into the cell chromosome
The main purpose of PCR is to _______.
amplify DNA
The polymerase chain reaction (PCR) is used in ______.
amplifying target DNA disease diagnosis
Cancer-causing chemicals are called
carcinogens
The consequences of not repairing damaged DNA in cells include ______.
cell death cancer (in animals)
Conjugation in bacteria requires ______.
contact between donor and recipient cell
Two methods used to identify mutants in a culture are ______ and ______ selection.
direct; indirect
Which step of the polymerase chain reaction (PCR) involves the synthesis of complementary strands of DNA?
elongation
True or false: Researchers performing genetic engineering can carry out their experiments unregulated, because this technology is so safe.
false
Which of the following are caused by chemical mutagens?
frameshift mutations base substitutions
A technique that allows scientists to study the expression of genes in organisms is called DNA ______.
microarray analysis
DNA ______ are used to study gene expression in organisms whose genome has already been sequenced.
microarrays
CRISPR systems involve ______.
retained segments of phage DNA used by bacteria to recognize and destroy future invading DNA
What process involves determining the order of nucleotides in a fragment of DNA?
sequencing
Base ______ mutations occur when an incorrect nucleotide is incorporated in place of another during DNA synthesis.
substitution
_______ is the transfer of bacterial DNA from a donor to recipient via a bacteriophage.
transduction
The process of bacterial------involves the uptake of "naked" DNA by competent bacterial recipient cells.
transformation
Mutagens that are DNA segments that can insert into genes and thereby inactivate them are called ______.
transposons
Restriction-modification systems were discovered ______.
while studying why certain bacterial strains are relatively resistant to phage infection
Arrange the following in the proper sequence in which they occur during a single PCR cycle. 1. Addition of DNA nucleotides by Taq polymerase 2. Complementary base pairing between primers and target DNA 3. Heat separation of strands of target DNA
3, 2, 1
selection is used to isolate an auxotroph from a prototrophic parent strain, because no selective medium exists to inhibit the parent.
Blank 1: Indirect or Negative
mutations are genetic changes caused by factors from outside of the cell such as radiation or chemicals.
Blank 1: Induced
are circular pieces of bacterial DNA that do not usually encode information essential to the life of a cell.
Blank 1: Plasmids
Protection against the toxic effects of antimicrobial compounds or heavy metals is often encoded on plasmids called---plasmids
Blank 1: R or resistance
Extensively damaged DNA activates the------repair mechanism, which cannot always determine the correct nucleotide sequence, thus introducing mutations resulting from the repair process itself.
Blank 1: SOS
In bacteria,-------refers to DNA transfer requiring cell to cell contact.
Blank 1: conjugation
What is the importance of the polymerase chain reaction (PCR)?
It can be used to increase the amount of a select region of DNA in a sample. It can be used to detect target DNA in a sample.
Which of the following statements about transformation is correct?
Transformation is the uptake of naked DNA from the environment.
______ are segments of DNA that can move from one location to another in a cell's genome.
Transposons
Which of the following types of radiation are mutagenic?
X-rays Ultraviolet rays
Because CRISPR systems involve bacteria using retained segments of DNA to identify and destroy future invading phage DNA, these systems are a form of ______.
adaptive immunity
Many bacteria are able to recognize and destroy invading DNA. It is thought this ability evolved ______.
as a defense against phages
is a virus that infects bacteria, and some can transfer bacterial genes from a donor cell to a recipient cell.
bacteriophages
Knowing the sequence of a genome is useful in which of the following applications?
identifying genetic alterations associated with disease studying evolutionary relationships determining protein sequences
An auxotroph can be isolated from a prototrophic parent strain by ______ selection.
indirect
Mutations that are caused by external influences such as radiation or chemicals are called ______ mutations.
induced
Fluorescence in situ hybridization (FISH) is used to detect specific nucleotide sequences within ______.
intact cells attached to a microscope slide
Is it as effective to take two antibiotics sequentially for an infection as it is to take them simultaneously, as long as the total length of time of the treatment is the same?
No. If the antibiotics are given sequentially, there is a chance that resistance to either one may arise through mutation. When antibiotics are given simultaneously, the chance of resistance to two different antibiotics occurring is extremely low.
Errors by DNA polymerase that incorporate the wrong nucleotide into replicating DNA can be repaired quickly by which two mechanisms?
Proofreading by DNA polymerase Mismatch repair
In conjugation the donor cell is recognized by the presence of
an F plasmid.
During the second step of a polymerase chain reaction (PCR) cycle, the temperature is lowered. This results in ______.
the primers annealing to their complementary sequences
Which is the correct labeling of the mutations in the figure?
1: synonymous; 2: nonsense; 3: missense
Consider the figure. If methylguanine replaces guanine in a DNA strand with the sequence 5'CGA3', the resulting change in the complementary strand after DNA replication would be
3'GTT5'.
Please select the INCORRECT statement regarding mutation.
A missense mutation is also called a synonymous mutation, meaning no change in the amino acid encoded.
frameshift mutation
A mutation resulting from an insertion or deletion of bases that causes a change in the reading frame of the mRNA.
The material responsible for transformation was shown to be DNA by
Avery, MacLeod, and McCarty.
In E. coli, less than 50% of the genes are found in all strains. These conserved genes are called the----genome.
Blank 1: core
True or false: In bacterial conjugation, all F+ donor cells are high frequency recombinant (Hfr) cells.
False
True or false: Plasmids are insertion sequences that can lead to changes in genotype within a cell or between cells.
False
Insertion sequences
are the simplest type of transposon, code for a transposase enzyme, AND are characterized by an inverted repea
Selecting penicillin-resistant mutants by plating them on a medium containing penicillin is an example of ______ selection.
direct
Indirect selection
is necessary to isolate auxotrophic mutants.
Planar molecules used as chemical mutagens are called
intercalating agents.
Which of the following is required for fluorescence in situ hybridization (FISH)?
labeled probe
A bacterial virus is known as a(n) _______.
phage
The organism's observable characteristics. For example, presence of a flagellum.
phenotype
Random genetic changes that result from normal cellular processes are ______
spontaneous mutations
Plasmids with a-------copy number occur in only one copy per cell, while those with a-------copy number are present in many copies per cell.
Blank 1: low Blank 2: high
In which of the following does the donor cell direct the process?
Conjugation
A missense mutation has a greater impact on a cell than does a frameshift mutation. Group starts True or False
false
Chemical mutagens often act by altering the
hydrogen bonding properties of the nucleobase.
Restriction-modification systems.
Modifying self-DNA shortly after it's produced, followed by using restriction endonucleases to digest DNA that lacks modification.
Using the genetic code (below), determine what type of mutation would occur if the last nucleotide in the codon AGA was converted to a U.
Missense
The process by which organisms best adapted to a given environment will predominate in that environment is called _______.
natural selection
