chapter 8 vocab and smartbook
DNA repair
In humans, two of the genes associated with the development breast cancer encode enzymes involved in ______.
bacteriophage
A ______is a virus that infects bacteria, and some can transfer bacterial genes from a donor cell to a recipient cell
transposons
Mutagens that are DNA segments that can insert into genes and thereby inactivate them are called ______.
direct and indirect
Mutant cells in bacterial cultures can be isolated by ___ selection and___selection methods
low; high
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
point mutation
Mutation in which only a single base pair is involved.
frameshift mutation
Mutation resulting from the addition or deletion of a number of nucleotides not divisible by 3
spontaneous mutations
Mutation that occurs naturally during the course of normal cell processes.
induced
Mutations that are caused by external influences such as radiation or chemicals are called ______ mutations.
spontaneous
Mutations that arise naturally during cellular metabolism, and not as a result of exposure to mutation-causing agents, are called ____mutations.
direct
Selecting penicillin-resistant mutants by plating them on a medium containing penicillin is an example of ______ selection.
SOS repair
Extensively damaged DNA activates the ____repair mechanism, which cannot always determine the correct nucleotide sequence, thus introducing mutations resulting from the repair process itself.
mutation and horizontal gene transfer
Genetic change in bacteria occurs through which two mechanisms?
photoreactivation
This figure shows the steps of ______, a process that repairs thymine dimers by breaking the covalent bonds that have formed between adjacent thymines
vertical gene transfer
Transfer of genes from parent to offspring.
indirect
An auxotroph can be isolated from a prototrophic parent strain by ______ selection.
competent cells
Cells that have the ability to take up DNA from the environment are called ______ cells.
base substitution frameshift mutation
Chemical mutagens can cause two types of mutations:
carcinogens; mutagens
Chemicals that cause cancer are known as ______, and most of them are ______.
contact between donor and recipient cell
Conjugation in bacteria requires ______.
horizontal gene transfer
DNA transfer from one organism to another by a process other than reproduction; in bacteria, this occurs by bacterial transformation, conjugation, or transduction.
DNA glycosylase
During repair of oxidized guanine, which enzyme removes the damaged nucleobase from the sugar-phosphate backbone?
Proofreading by DNA polymerase Mismatch repair
Errors by DNA polymerase that incorporate the wrong nucleotide into replicating DNA can be repaired quickly by which two mechanisms?
conjugation
The F or fertility plasmid contains genes that are required for bacterial ______.
cell death cancer (in animals)
The consequences of not repairing damaged DNA in cells include ______.
core genome
The genes that are present in all strains of a given species are called the ______.
transduction
The mechanism by which bacterial DNA is moved from one bacterium to another by a bacteriophage is called
base substitution
The most common type of mutation is base _____where an incorrect nucleotide is incorporated during DNA replication
transformation
The process of bacterial___involves the uptake of "naked" DNA by competent bacterial recipient cells.
base excision repair
The type of DNA damage repair illustrated here is
Transformation is the uptake of naked DNA from the environment.
Which of the following statements about transformation is correct? -Transformation is the uptake of naked DNA from the environment. -Transformation involves the formation of a sex pilus through which plasmid DNA is shared between bacteria. -Transformation depends on a donor cell containing an F plasmid and a recipient cell that does not. -Transformation is the transfer of DNA from one bacterial cell to another by means of a bacteriophage.
Ultraviolet rays X-rays
Which of the following types of radiation are mutagenic?
induced
___ mutations are genetic changes caused by factors from outside of the cell such as radiation or chemicals.
Transposons (jumping genes)
______ are segments of DNA that can move from one location to another in a cell's genome.
SOS repair
______ repair is activated by extensive DNA damage and uses a polymerase that lacks proofreading ability, ultimately resulting in mutations.
Transduction
_______ is the transfer of bacterial DNA from a donor to recipient via a bacteriophage.
induced
______mutations are genetic changes caused by factors from outside of the cell such as radiation or chemicals.
point mutation
a ___mutation occurs if a single base pair is changed during DNA synthesis.
a frameshift
mutation results from an insertion or deletion of nucleotides, leading to a shift of the reading frame from the point of mutation downstream.
indirect
selection is used to isolate an auxotroph from a prototrophic parent strain, because no selective medium exists to inhibit
competent
A bacterial cell described as____can take up DNA from the surrounding environment.
phage
A bacterial virus is known as a(n) _______.
RNA ; protein
A bacteriophage consists of a genome made up of DNA or______surrounded by a coat made up of_____
Mutation
A change in the nucleotide sequence of a cell's DNA that is passed on to daughter cells.
base substitution mutation
A mutation in which the wrong nucleotide has been incorporated.
direct; indirect
Two methods used to identify mutants in a culture are ______ and ______ selection.
F'
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 ______.
Transformation
Which mechanism of gene transfer involves the uptake of "naked" DNA by competent bacterial recipient cells?
base substitutions frameshift mutations
Which of the following are caused by chemical mutagens?
transduction, transformation, conjugation
Which of the following are the three main methods of gene transfer in bacteria?
nucleotide excision repair
Which type of DNA repair is shown in this figure?
DNA or RNA genome protein coat
can be found in a bacteriophage?
core
In E. coli, less than 50% of the genes are found in all strains. These conserved genes are called the__________genome.
horizontal ; vertical
In ______gene transfer, DNA moves from one organism to another, while in _____gene transfer, DNA is passed from a parent cell to its progeny.
a cell in which the F plasmid has been integrated into the cell chromosome
In conjugation in E. coli, an Hfr cell refers to ______.
transformation, transduction, & conjugation
In prokaryotes, genes can be transferred from a donor to a recipient via three different mechanisms:
proofreading mismatch
Repair of nucleotide incorporation errors during the process of DNA replication is accomplished by ____________by DNA polymerase and by ______repair.