Genetics Exam #3 MC Questions

A repressor is a _____ that _____ transcription.

regulatory transcription factor, inhibits

Which of the follow combinations will cause the rate of transcription to increase?

a repressor plus an inducer

What is an operon?

a group of genes under the control of a single promoter

The binding of _____ to lac repressor causes lac repressor to _____ to the operator site, thereby _____ transcription.

allolactose, not bind, increasing

How does exposing an E. coli cell to glucose affect the regulation of the lac operon via CAP?

cAMP does not bind to CAP and transcription is decreased

When tryptophan binds to trp repressor, this causes trp repressor to _____ to the trp operator and _____ transcription.

bind, inhibit

During attenuation, when tryptophan levels are high, the _____ stem-loop forms and transcription _____ the trpL gene.

3-4, ends just past

Operons involved with the biosynthesis of molecules such as amino acids are most likely to be regulated in which of the following ways?

the product of the biosynthetic pathway represses transcription

Translation can be regulated by

all of the above

An example of a posttranslational covalent modification that may affect protein function is

all of the above

For a riboswitch that controls transcription, the binding of a small molecule such as TPP controls whether the mRNA

has an antiterminator or terminator stem loop

RTFs can be modulated by

all of the above

A chromatin-remodeling complex may

all of the above

According to the histone code hypothesis, the pattern of histone modifications acts like a language that

influences chromatin structure

How can methylation affect transcription?

all of the above

A coactivator may

all of the above

The method of ChIP-Seq is used to

determine the locations of genes on a genome-wide level

An epigenetic modification to a specific gene may initially be established by

all of the above

Heterochromatin is characterized by which of the following?

all of the above

A mutation changes a codon that specifies tyrosine into a stop codon. This type of mutation is a

nonsense mutation

Which of the following is not an example of a spontaneous mutation?

a mutation caused by UV light

A point mutation could be caused by

all of the above

One way that TNRE may occur involves the formation of _____ that disrupts _____.

a hairpin, DNA replication

A mutagen that is a base analog is

5-bromouracil

In an Ames test, a _____ number of colonies is observed if a substance _____ a mutagen, compared with the number of colonies for a control sample that is not exposed to the suspected mutagen.

significantly higher, is