Chapter 8A: Bacterial Genetics
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
The ___ is the nucleotide sequence in the DNA of a cell or an organism.
genotype
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
A(n) ___ mutation is a base substitution that changes the codon to one that specifies a different amino acid.
missense
An organism that has a mutation is called a ___.
mutant
Organisms most fit to survive in a given environment will predominate because they can reproduce more rapidly than others. This phenomenon is called ___ ___.
natural selection
A base substitution that leads to the creation of a stop codon is called a(n) ___ mutation.
nonsense
A(n) ___ mutation occurs if a single base pair is changed during DNA synthesis.
point
The return of a gene from a mutated state to its original, non-mutated state is called a ______.
reversion
Base ______ mutations occur when an incorrect nucleotide is incorporated in place of another during DNA synthesis.
substitution
The most common type of mutation is base ___, where an incorrect nucleotide is incorporated during DNA replication
substitution
A base substitution that results in a codon that still codes for the wild type amino acid is called a(n) ______ mutation.
synonymous
Segments of DNA that can move to new positions within the genome of a single cell are called ___.
transposons
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: 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 terms describes the sequence of nucleotides (genetic makeup) of an organism or a cell?
Genotype
___ mutations are genetic changes caused by factors from outside of the cell such as radiation or chemicals.
Induced
Which term refers to an organism that has a mutation?
Mutant
The process by which organisms best adapted to a given environment will predominate in that environment is called _______.
Natural Selection
___ is the change of a mutated genetic sequence back to its original, non-mutated form.
Reversion
If a scientist is working with bacteria that have the typical phenotype of those isolated from nature, the bacteria are considered to be ______ type.
wild
The term used to describe a gene when it is found in its natural, non-mutated, form is ___ type.
wild
The native or ___ ___ strain describes cells that carry non-mutated DNA.
wild type
Which of the following are caused by chemical mutagens?
- base substitutions - frameshift mutations
Chemical mutagens can cause two types of mutations: ___ substitutions and ___ mutations.
base; frameshift
Mutagens that modify nucleobases change their ___-___ properties.
base, pairing
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
Genetic change in bacteria occurs through which two mechanisms?
- Horizontal gene transfer - mutation
Which of the following are possible outcomes of a base substitution?
- synonymous mutation - nonsense mutation - missense mutation
If a base substitution changes an amino acid-encoding codon to a stop codon what would it be called?
Nonsense mutation
Which of the following describes an organism's observable characteristics?
Phenotype
___ are DNA segments that increase the rate of mutations by inserting themselves into genes and inactivating them.
Transposons
______ are segments of DNA that can move from one location to another in a cell's genome.
Transposons
Base ______ structurally resemble nucleobases and can be mistakenly incorporated into nucleotides and then into DNA.
analogs
Mutations that are caused by external influences such as radiation or chemicals are called ______ mutations. Multiple choice question.
induced
A base substitution that results in a change in the amino acid encoded is called a(n) ______ mutation. Multiple choice question.
missense
A(n) ___ mutation is a base substitution that does not change the encoded amino acid.
silent or synonymous
A base substitution in a protein-encoding gene results in one of three possible mutation outcomes: ___ mutation, ___ mutation, or ___ mutation.
silent; missense; nonsense
Mutations that arise naturally during cellular metabolism, and not as a result of exposure to mutation-causing agents, are called ___ mutations.
spontaneous
Random genetic changes that result from normal cellular processes are ______.
spontaneous mutations
Spontaneous mutations are important because ______.
they allow populations of bacteria to adapt to a changing environment
True or false: The native or wild type strain describes the typical phenotype of strains isolated from nature.
True
A(n) ___ is a change in the nucleotide sequence of DNA that is passed on to daughter cells.
mutation
True or false: A point mutation involves any substitution of a single nucleotide.
True
