Hardest Test On Microbiology! Trivia Quiz

Mutations resulting from exposure to physical or chemical agents are called __________ mutations.  

__________ mutations occur in the promoter or operator region of a gene or set of genes and affects the expression of the downstream genes without affecting the amino acid sequences of the gene products.  

In mismatch repair on newly replicated DNA, enzymes distinguish between old and newly replicated DNA strands based on the fact that newly replicated DNA strands are ________ methylated relative to older DNA.  

__________ __________ is the process by which some cells are capable of degrading an exogenote. (2 words)  

A __________ is a piece of extrachromosomal DNA that has its own replication origin.  

 A plasmid that can either exist independently of the chromosome or be integrated into it is called a(n) __________.  

In order to take up a naked DNA molecule, a cell must be __________, which may occur only at certain stages in the life cycle of the organism.  

__________ mutations affect only a single base pair in a gene.  

Plasmids that have genes for pili and can transfer copies of themselves to other bacteria during conjugation are called __________ plasmids.  

A __________ is a latent form of a virus genome that remains within the host without destroying it.  

__________ are physical or chemical agents that cause mutation.  

Photoreactivation repairs thymine dimers by splitting them back into separate thymines.  

• True

• False

Transformation has been observed in only a limited number of species in nature, but we have found ways to force the process upon other species in the laboratory.  

• True

• False

A recipient cell that is temporarily diploid for a portion of the genome during the replacement process is called a(n) __________.  

• Merozygote

• Exogenote

• Endogenote

• None of the choices

Approximately half of known animal carcinogens can be detected by the Ames test.  

• True

• False

Repair of thymine dimers using light to split the dimers apart into separate monomers is called  

• Photodedimerication.

• Photoreactivation

• Photoreparation

• None of the choices

Plasmids that have genes that decrease bacterial susceptibility to antibiotics are called __________ factors.  

• Col

• Resistance

• Virulence

• Metabolic

_______ are strains that are unable to grow on a minimal medium that supports growth of the wild type strain but are able to grow on the minimal medium if one or more nutritional supplements are added.  

• Autotrophs

• Auxotrophs

• Portotrophs

• Minitrophs

Mutations that result in the death of an organism when expressed are called __________ mutations.  

• Dominant

• Recessive

• Lethal

• Conditional

A __________ mutation is one that causes premature termination of the synthesis of the protein product.  

• Missense

• Nonsense

• Silent

• None of the choices

 In an HFR  F⁺ mating, the conjugation bridge usually breaks before chromosomal transfer is complete. Therefore, the recipient remains F^-.  

• True

• False

A mutation from the most prevalent form of a gene to a mutant form is called a __________ mutation.  

• Forward

• Reverse

• Wild card

• Escalating

A __________ mutation does not alter the amino acid sequence of the resulting protein.  

• Missense

• Nonsense

• Silent

• None of the choices

 Transfer of genes from one mature independent organism to another is called  

• Horizontal gene transfer.

• Lateral gene transfer.

• Vertical gene transfer.

• Orthogonal gene transfer.

A reciprocal exchange in which a pair of DNA with the same nucleotide sequence break and rejoin in a crossover is called __________ recombination.  

• Homologous

• Site-specific

• Replicative

• None of the choices

 In the mechanics of conjugation, exclusive of gene transfer, Hfr and F⁺ strains behave the same.  

• True

• False

The Ames test  

• Can be used to measure the mutagenicity of chemicals.

• Is used to measure the repair of thymine dimers.

•  is used to measure levels of oxygen free radicals.

• None of the choices

The genome of a recipient cell is called a(n) __________.  

• Merozygote

• Exogenote

• Endogenote

• None of the choices

Lethal mutations can be maintained in diploid organisms if they are  

• Dominant

• Recessive

• Deletions

• None of the choices

Alternate forms of genes resulting from mutations are called  

• Isoforms

• Alterons

• Alleles

• Lethal

The process in which one or more nucleic acid molecules are rearranged or combined to produce a new nucleotide sequence is called  

• Transformation

• Conjugation

• Recombination

• Transduction

Which of the following is a possible fate for an exogenote?  

•  integration into the host chromosome

•  independent replication and functioning

• Degradation to nucleotides

• All of the choices

Which of the following effects may be mediated by transposable elements?  

• Insertion into a gene, causing a mutation.

• Activation of nearby genes.

• Formation of genetic deletions.

• All of the choices.

In an F⁺  F^- conjugation, the donor is the __________ strain.  

• F+

• F-

• Both F+ and F- (It is a reciprocal exchange)

• Neither F+ nor F- (There is no exchange)

A mutagen that inserts between the stacked bases of a DNA double helix, distorting the DNA to induce single-pair insertions or deletions is called a(n) __________ agent.  

• Insertional

• Interspersing

• Intercalating

• Distortional

 Insertion sequences are  

• normally relatively short (700 to 1,650 bp). 


• capable of transposition.

• Are discrete genetic elements bounded at both ends with inverted repeats.

• All of the choices

When a recipient cell acquires a piece of naked DNA from the environment, it is called  

• Conjugation

• Transformation

• Transduction

• Transfection

Which of the following types of mutation may play an important role in driving evolution because they are often nonlethal and, therefore, remain in the gene pool?  

• Nonsense

• Missense

• Frameshift

• Deletion

Site-specific recombination systems  

• Do not depend on extensive nucleotide sequence homology.

• Depend on enzymes that are often specific for sequences within the host.

•   are features of some viruses. 


• All of the the choices are true

 After an F⁺  F^- mating, the donor is __________ and the recipient is __________.  

• F+; F-

• F-; F+

• F-; F-

• F+; F+

Which of the following occurs with generalized transduction?  

• Degradation of the host chromosome into randomly sized fragments

• Packaging of any DNA fragment of the appropriate size

• Transfer of any bacterial gene to the subsequent host

• All of these occur with generalized transduction.

Which of the following can lead to transition mutations?  

• Incorporation of a base analog that exhibits different base-pairing properties from the base it replaces

• Chemical modification of an existing base in the DNA so that in the next round of replication it will pair differently from the unmodified base

• Incorporation of a base analog that exhibits different base-pairing properties from the base it replaces and chemical modification of an existing base in the DNA so that in the next round of replication it will pair differently from the unmodified base


• A small insertion or deletion

A mutation that changes the amino acid sequence of the resulting protein by substitution is called a __________ mutation.  

• Missense

• Nonsense

• Silent

• None of the choices

Which of these transposable elements do not carry genes for functions other than those needed for transposition?  

• Insertion sequences

• Composite transposons

• Retrotransposons

• Conjugal transposons

 Transfer of genetic information via direct cell-cell contact is called  

• Transformation

• Transduction

• Transfection

• Conjugation

Which of the following is the most error-prone of the repair mechanisms?  

•  postreplication repair

• Recombination repair

• SOS repair

• Photoreactivation

SOS repair  

• Requires RecA protein.

• Is inducible by DNA damage.

•  is error prone, i.e., produces mutations.


• All of the choices

As the result of exposure to a mutagen, cytosine is substituted for thymine in one strand of DNA. Upon subsequent DNA replication, one of the daughter cells will have a GC pair in this position instead of an AT pair. This is called a(n) __________ mutation.  

• Transversion

• Transition

• Frameshift

• Insertion