Biology - Ch 8 Bacterial Genetics
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 Other way around
______ is used to fix nucleotide incorporation errors that are missed by the proofreading function of DNA polymerase. Photoactivation Mismatch repair Polymerase repair Excision repair SOS repair
Mismatch repair
A bacteriophage consists of a genome made up of DNA or _____, surrounded by a coat made up of _____
RNA protein
The F or fertility plasmid contains genes that are required for bacterial ______. competence transduction conjugation transformation
conjugation
A plasmid that can directs its own transfer from donor to recipient cells is called a(n) _____ plasmid
conjugative
Mutations that are caused by external influences such as radiation or chemicals are called ______ mutations. induced anonymous transposable spontaneous
induced
In _____ gene transfer, DNA moves from one organism to another, while in _____ gene transfer, DNA is passed from a parent cell to its progeny.
horizontal vertical
A(n) _____ is a change in the nucleotide sequence of DNA that is passed on to daughter cells.
mutation
Genetic change in bacteria occurs through which two mechanisms? mutation horizontal gene transfer vertical gene transfer
mutation horizontal gene transfer
DNA in the environment that is not contained within a cell or virus is called _____ DNA
naked
A plasmid that can directs its own transfer from donor to recipient cells is called a(n) pilus membrane cilium fimbria receptor
pilus
In prokaryotes, genes can be transferred from a donor to a recipient via three different mechanisms: _____, _____ and _____
bacterial transformation transduction conjugation
A(n) _____ is a virus that infects bacteria, and some can transfer bacterial genes from a donor cell to a recipient cell.
bacteriophages
Mutagens that modify nucleobases change their _____ - _____ properties
base pairing
A(n) _____ mutation occurs if a single base pair is changed during DNA synthesis.
point
During bacterial conjugation, synthesis of a new strand of F plasmid DNA occurs in ______. both the donor and recipient either the donor or the recipient, but not both the recipient only the donor only neither the donor nor the recipient
both the donor and recipient
Random genetic changes that result from normal cellular processes are ______. spontaneous mutations induced mutations synonymous mutations
spontaneous mutations
The most common type of mutation is base _____ , where an incorrect nucleotide is incorporated during DNA replication.
substitution
True or false: Incorporation of an incorrect nucleotide in a molecule of DNA results in a distortion of the DNA helix that can be detected by repair enzymes.
True
The majority of transposons contain _______ terminators. translational replicational transcriptional
transcriptional
The _____ is the observed characteristics of an organism.
phenotype
Repair of nucleotide incorporation errors during the process of DNA replication is accomplished by _____ by DNA polymerase and by _____ repair
proofreading mismatch
When bacteriophages replicate, phage components are synthesized in the host cell and assemble into new viruses ______. within that cell before being released when the bacterial cell enters a new eukaryote host within the nucleus of the host cell before release after the components are released from the host cell
within that cell before being released
A base substitution that leads to the creation of a stop codon is called a(n) _____ mutation
nonsense
Chemical mutagens that modify ______ increase the odds of incorrect nucleotide incorporation during DNA replication. amino acids monosaccharides nucleobases pentose sugars
nucleobases
A(n) _____ mutation is a base substitution that does not change the encoded amino acid.
silent / synonymous
Mutations that arise naturally during cellular metabolism, and not as a result of exposure to mutation-causing agents, are called _____ mutations
spontaneous
A base substitution that results in a codon that still codes for the wild type amino acid is called a(n) ______ mutation. frameshift missense insertion synonymous deletion
synonymous
Which of the following types of radiation are mutagenic? x rays infrared rays ultraviolet rays
ultraviolet rays x rays
Conjugation in bacteria requires ______. formation of a biofilm matrix the isolation of chromosome fragments the presence of bacteriophages contact between donor and recipient cell
contact between donor and recipient cell
The _____ is the nucleotide sequence in the DNA of a cell or an organism.
genotype / genome
Which of the following are characteristics of recombinants? The have properties of both donor and recipient cells. They have multiple chromosomes. They are genetically identical to their parent strain. They result from horizontal gene transfer.
The have properties of both donor and recipient cells. They result from horizontal gene transfer.
A(n) _____ mutation is a base substitution that changes the codon to one that specifies a different amino acid.
missense
The total set of mobile genetic elements is called a(n) _____
mobileome
_____ _____ are a type of radiation that can cause single and double stranded breaks in a DNA strand.
x rays
The consequences of not repairing damaged DNA in cells include ______. cancer (in animals) cell death increased activity of RNA polymerase cells that have fewer mutations
cell death cancer (in animals)
True or false: A point mutation involves any substitution of a single nucleotide.
True Reason: A point mutation involves any substitution of a single nucleotide that does not change the DNA reading frame.
Genes into which transposons "jump" are usually ______ by the event. activated unaffected inactivated
inactivated
An organism that has a mutation is called a _____
mutant
Recognition and repair of errors in nucleotide incorporation by DNA polymerase is called ______. mismatch repair proofreading excision repair photoactivation
proofreading
______ sometimes incorporates the incorrect nucleotide when generating a new strand of DNA during DNA ______; this leads to a detectable distortion in the DNA helix. RNA polymerase; replication DNA polymerase; replication RNA polymerase; transcription DNA polymerase; transcription
DNA polymerase; replication
______ are segments of DNA that can move from one location to another in a cell's genome. Transcripts Mutagens Transposons Plasmids
Transposons
In bacteria, _____ refers to DNA transfer requiring cell to cell contact.
conjugation
When horizontal gene transfer occurs between a donor and recipient cells, the resulting cells are called _____
recombinants
In humans, two of the genes associated with the development breast cancer encode enzymes involved in ______. cell death DNA damage mutagenesis DNA repair
DNA repair
_____ mutations are generally the most harmful to cells because they change all of the codons downstream of the mutation.
frameshift
Chemical mutagens can cause two types of mutations: _____ substitutions and _____ mutations
base frameshift
Which of the following are the three main methods of gene transfer in bacteria? translocation conjugation transduction transposition competition transformation
transformation transduction conjugation
mutations are genetic changes caused by factors from outside of the cell such as radiation or chemicals.
induced
Base ______ mutations occur when an incorrect nucleotide is incorporated in place of another during DNA synthesis. translocation insertion substitution deletion
substitution
Segments of DNA that can move to new positions within the genome of a single cell are called _____
transposons
Mutation rates are low because proofreading and _____ mechanisms fix altered or damaged DNA before it can be passed to progeny.
repair mismatch repair DNA repair
These chemicals, produced in aerobic environments, result in increased base substitution because they oxidize guanine in DNA. - reactive oxygen species (ROS) - quaternary ammonium compounds - major histocompatibility complexes (MHC) - intercalating agents
reactive oxygen species (ROS)
Base substitutions are more common in aerobic vs. anaerobic environments because of the production of ______ under aerobic conditions. ATP guanine nucleotides reactive oxygen species DNA polymerase
reactive oxygen species
During conjugation, the F plasmid nucleic acid that transfers is ______. double-stranded DNA double-stranded RNA single-stranded RNA single-stranded DNA
single-stranded DNA
Many DNA polymerases have the ability to detect and repair their own errors in nucleotide incorporation. This ability is called _____
proofreading
Which is an agent that induces changes in DNA? mutation mutant mutagen
mutagen
Which term refers to an organism that has a mutation? Mutant Mutagen Wild type
Mutant
A _____ is an agent that induces changes in DNA.
mutagen
In E. coli, less than 50% of the genes are found in all strains. These conserved genes are called the _____ genome
core
Sometimes DNA polymerase adds the wrong nucleotide to the growing chain. If proofreading does not fix the error, then it is usually fixed by a mechanism called _____ repair
mismatch
Which of the following are sources of "naked" DNA? Secreted into the environment by bacteria Contained within bacteria that lack cell walls Contained in bacteriophages Lysed (burst) bacterial cells
Secreted into the environment by bacteria Lysed (burst) bacterial cells
Errors by DNA polymerase that incorporate the wrong nucleotide into replicating DNA can be repaired quickly by which two mechanisms? Excision repair Photoactivation Proofreading by DNA polymerase SOS repair Mismatch repair
Proofreading by DNA polymerase Mismatch repair
Ultraviolet radiation causes covalent bonds to specifically form between adjacent _____ molecules on a DNA molecule.
thymine / pyrimidine
Ultraviolet radiation causes a very specific type of DNA damage called ______. transduction recombination base analogs thymine dimers double-strand breaks
thymine dimers
The mechanism by which bacterial DNA is moved from one bacterium to another by a bacteriophage is called _____
transduction
The process of bacterial _____ involves the uptake of "naked" DNA by competent bacterial recipient cells.
transformation
True or false: Ultraviolet rays are chemical mutagens.
False
During repair of oxidized guanine, which enzyme removes the damaged nucleobase from the sugar-phosphate backbone? DNA ligase RNA polymerase DNA polymerase DNA glycosylase helicase
DNA glycosylase
Which of the following can be found in a bacteriophage? nucleus hybrid DNA/RNA genome DNA or RNA genome protein coat protein genome lipid membrane
DNA or RNA genome protein coat
True or false: A point mutation always leads to a shift of the reading frame from the point of mutation downstream.
False
Which of the following terms describes the sequence of nucleotides (genetic makeup) of an organism or a cell? Haplotype Genotype Serotype Phenotype
Genotype
Which of the following describes an organism's observable characteristics? Genotype Haplotype Phenotype Serotype
Phenotype
X rays can cause which types of damage to a DNA molecule? Double stranded breaks Nucleobase alterations Thymine dimer formation Single stranded breaks
Single stranded breaks Double stranded breaks Nucleobase alterations
_______ is the transfer of bacterial DNA from a donor to recipient via a bacteriophage. Transformation Transposition Conjugation Transduction
Transduction
Which mechanism of gene transfer involves the uptake of "naked" DNA by competent bacterial recipient cells? Transformation Transduction Transposition Conjugation
Transformation
A common consequence of a _____ mutation is the appearance of an early stop codon that produces a shortened and thus non-functional protein.
frameshift
A(n) _____ mutation results from an insertion or deletion of nucleotides, leading to a shift of the reading frame from the point of mutation downstream.
frameshift
Which of the following mutations frequently results in the production of a shortened and non-functional protein because a different set of codons is translated? Frameshift Nonsense Point Base substitution Missense Silent
frameshift
Which of the following are caused by chemical mutagens? frameshift mutations double stranded breaks base substitutions thymine dimers
frameshift mutations base substitutions
There are two types of transduction: _____ , which transfers any genes of the donor cell, and _____, which transfers only a few specific genes.
generalized specialized
Transduction exists in two kinds. What are they? nonspecific localized generalized specialized specific compartmentalized
generalized specialized
Consider a population of bacteria susceptible to an antimicrobial. If a bacterium acquires a spontaneous mutation that gives resistance to the antimicrobial, this bacterium will ______ if the population is exposed to the antimicrobial. grow without competition not grow as well as all the other bacteria grow as well as all the other bacteria
grow without competition
During DNA replication, the template strand can be distinguished from the newly synthesized strand by the presence of _____ groups on certain nucleobases. This is very important for mismatch repair.
methyl
A base substitution that results in a change in the amino acid encoded is called a(n) ______ mutation. nonsense deletion missense silent frameshift
missense
Consider a base substitution mutation that occurs in a codon that specifies the amino acid tryptophan. If it leads to a different amino acid, the mutation is called _____ mutation, and if the resultant codon is a stop codon, then the mutation is termed a(n) _____ mutation
missense nonsense
Genes that vary considerably among strains of a species are likely to be ______. mobile genetic elements the core genome auxiliary genetic elements the pan genome
mobile genetic elements
Mutations are rare because ______. mutated DNA cannot be replicated, so it cannot be passed to progeny most damage is repaired before it is passed on to progeny damage to DNA is a very uncommon event
most damage is repaired before it is passed on to progeny
If a base substitution changes an amino acid-encoding codon to a stop codon what would it be called? nonsense mutation silent mutation deletion mutation missense mutation frameshift mutation
nonsense mutation
The sum total of genes encoded by all strains of a given species is called the _____-_____
pan genome
The entire set of genes found in all three strains of this particular species is known as the ______. core genome meta-genome super genome pan-genome
pan-genome
A bacterial virus is known as a(n) _______. prion bacteriovirus retrovirus elementary body phage
phage
The genes that are present in all strains of a given species are called the ______. plasmid genome basal genome core genome pan genome
core genome
A base substitution in a protein-encoding gene results in one of three possible mutation outcomes: _____ mutation, _____ mutation or _____ mutation
synonymous / silent missense nonsense
Which of the following are possible outcomes of a base substitution? synonymous mutation frameshift mutation nonsense mutation missense mutation thymine dimer mutation
synonymous mutation missense mutation nonsense mutation
Place the steps of F plasmid transfer in the correct order. Start with the earliest at the top. Complement of the transferred strand is synthesized. Single strand of F plasmid is transferred to the recipient cell. F pilus makes contact with recipient cell. One strand of F plasmid is cut in origin of transfer.
1. F pilus makes contact with recipient cell. 2. One strand of F plasmid is cut in origin of transfer. 3. Single strand of F plasmid is transferred to the recipient cell. 4. Complement of the transferred strand is synthesized.
After new virus particles have assembled in the bacterial host cell, they are usually ______. integrated into the structure of the bacterial cell wall released as a result of host cell lysis stored inside the cell for a later time destroyed by the bacterial immune system
released as a result of host cell lysis
Spontaneous mutations are important because ______. they allow horizontal gene transfer between bacteria they allow populations of bacteria to adapt to a changing environment
they allow populations of bacteria to adapt to a changing environment