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