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