Question 1

The gene products encoded by trans-acting elements perform their function by
A) associating with regulatory sequences distant from the gene from which they were transcribed.
B) regulating the expression of the gene from which they were transcribed.
C) the association of nucleotides with the elongating RNA transcript.
D) physically associating with DNA polymerase.
E) regulating the activity of telomerase.

Accepted Answer

Trans-acting elements, such as transcription factors and RNA binding proteins, bind to regulatory sequences on the DNA that are often far away from the gene they are transcribed from. This allows for regulation of gene expression from a distance.

Question 2

In generating a reporter construct to study gene regulation,the reporter gene introduced replaces
A) beta-galactosidase.
B) a random region of DNA.
C) the cis-acting regulatory DNA sequence.
D) X-gal.
E) the coding region of the gene being studied.

Accepted Answer

To study gene regulation, a reporter construct is created by introducing a reporter gene that replaces the coding region of the gene being studied. The reporter gene's expression is then used as a surrogate measure of the activity of the endogenous gene's regulatory elements. Therefore, answer E is the best choice.

Question 3

Mutations introduced into reporter constructs are used to study
A) the DNA sequences that are important for regulating gene expression levels.
B) the effects on cell function of expression of heterologous proteins.
C) colorimetric assays.
D) protein-protein interactions.
E) Western blots.

Accepted Answer

Mutations introduced into reporter constructs are commonly used to study the DNA sequences that are important for regulating gene expression levels. These mutations can disrupt or enhance transcription factor binding sites, promoter regions, and other sequences that affect gene expression. By measuring the reporter gene expression in response to these mutations, researchers can pinpoint the specific DNA sequences necessary for proper gene regulation.

Question 4

The __________________________ is the cis-acting DNA sequence that serves as the binding site for RNA polymerase.
A) promoter
B) terminator
C) enhancer
D) regulator
E) initiator

Accepted Answer

The promoter is the cis-acting DNA sequence that serves as the binding site for RNA polymerase. The other choices (terminator, enhancer, regulator, initiator) are also regulatory elements involved in transcription, but they do not directly bind RNA polymerase.

Question 5

Which of the following is not true of enhancer DNA sequences?
A) They contain the TATA box regulatory element.
B) They may be located upstream of a TATA box.
C) They can be more than 10 kilobases from the gene they regulate.
D) They may increase or decrease gene transcription levels.
E) They may contain multiple regulatory elements.

Accepted Answer

Enhancer DNA sequences do not contain the TATA box regulatory element, which is typically found in promoter regions.

Question 6

Which of these is most important to ChIP (chromatin immunoprecipitation)technology?
A) an antibody that recognizes specific chromatin structures
B) an antibody that recognizes a nucleosome
C) an antibody that recognizes a transcription factor of interest
D) an antibody that recognizes the DNA cis-element of interest
E) an antibody that recognizes the promoter of interest

Accepted Answer

ChIP technology relies on immunoprecipitation of a specific transcription factor of interest. Antibodies that recognize other chromatin structures (A and B) or DNA elements such as cis-elements or promoters (D and E) may be useful in other assays but are not specific to ChIP.

Question 7

Zinc-finger peptide motifs are responsible for what aspect of protein function?
A) kinase activity
B) DNA binding
C) mRNA splicing
D) DNA replication
E) methylation

Accepted Answer

Zinc-finger peptide motifs are responsible for DNA binding, allowing proteins to interact specifically with certain sequences of DNA.

Question 8

_______________ motifs function to promote the DNA-binding activity of many transcriptional activator proteins.
A) ABP
B) Zinc-finger
C) Basolateral
D) Leucine zipper
E) Medial cleft

Accepted Answer

The answer of _______________ motifs function to promote the DNA-binding...

Question 9

Mutations altering the amount of protein synthesized from a reporter construct occur most often in which of the following sequences of DNA?
A) the reporter gene
B) cis-acting DNA elements
C) X-gal coding sequence
D) RNA polymerase II gene
E) the introns of the reporter gene

Accepted Answer

Mutations in cis-acting DNA elements, such as enhancers or promoters, can affect the amount of protein synthesized from a reporter construct by altering the level of expression of the reporter gene. Mutations in the other sequences listed may affect other aspects of gene expression or translation, but are less likely to directly impact the amount of protein synthesized.

Question 10

Transcription in prokaryotes and eukaryotes is similar in that
A) transcriptional machinery controls compaction and decompaction of chromatin.
B) the mRNA produced can undergo alternative splicing.
C) both prokaryotic and eukaryotic proteins have identical affinities for DNA.
D) both are contained within the cell nucleus.
E) both are regulated by attachment of proteins to DNA adjacent to the gene being transcribed.

Accepted Answer

Both prokaryotic and eukaryotic transcription involve the regulation by proteins that bind to DNA sequences adjacent to the genes being transcribed. These regulatory proteins can either enhance or repress the transcription of genes by influencing the ability of RNA polymerase to access the DNA.

Question 11

Trans-acting proteins that influence transcription are commonly referred to as
A) DNA polymerases.
B) tumor suppressors.
C) enhancers.
D) transcription factors.
E) promoter elements.

Accepted Answer

Trans-acting proteins that influence transcription are commonly referred to as transcription factors.

Question 12

RNA polymerase I synthesizes _________ using a DNA template.
A) dsRNA
B) mRNA
C) tRNA
D) snRNA
E) rRNA

Accepted Answer

RNA polymerase I is responsible for synthesizing rRNA (ribosomal RNA) using a DNA template. Therefore, option E is the correct answer.

Question 13

A cis-acting DNA sequence that modulates the basal rate of transcription of a gene is termed a(n)
A) repressor.
B) activator.
C) promoter.
D) enhancer.
E) initiator.

Accepted Answer

An enhancer is a cis-acting DNA sequence that can increase the rate of transcription of a gene. It does this by binding to specific transcription factors, which then recruit the RNA polymerase complex to the promoter to initiate transcription. The other answer choices (repressor, activator, promoter, initiator) are all involved in regulating gene expression, but do not specifically modulate the basal rate of transcription.

Question 14

DNA sequences that serve as binding sites for proteins regulating transcription and are often found adjacent to a gene are said to be
A) cross-reacting.
B) cis-acting.
C) trans-acting.
D) origins of transcription.
E) transcription factors.

Accepted Answer

Binding sites for proteins regulating transcription that are adjacent to a gene are said to be cis-acting, meaning they affect the expression of the gene on the same DNA molecule. Cross-reacting refers to an immune response, origins of transcription are specific DNA sequences where transcription starts, transcription factors are proteins that bind to DNA sequences and regulate transcription, and trans-acting refers to factors that affect the expression of genes on different DNA molecules.

Question 15

______________ are cis-acting DNA sequences that often function at a distance from the gene they are regulating.
A) Promoter elements
B) Terminator elements
C) Enhancer elements
D) Regulator elements
E) Initiator elements

Accepted Answer

Enhancer elements are cis-acting DNA sequences that often function at a distance from the gene they are regulating. Promoter elements are located near the gene's start site and are involved in initiating transcription. Terminator elements are located near the end of the gene and are involved in stopping transcription. Regulator elements and Initiator elements are not commonly recognized as distinct types of cis-acting DNA sequences.

Question 16

tRNA molecules are transcribed by
A) DNA pol II.
B) DNA pol III.
C) RNA pol I.
D) RNA pol II.
E) RNA pol III.

Accepted Answer

tRNA molecules are transcribed by RNA polymerase III (RNA pol III) in the nucleus of eukaryotic cells. RNA pol III is responsible for transcribing many small functional RNA molecules, including tRNAs, 5S rRNA, and some other small regulatory RNAs.

Question 17

_____________ are basal transcription factors that associate with TBP to assist in initiating transcription from eukaryotic class II genes.
A) TATAs
B) DNA-BPs
C) TAFs
D) Jun and Fos
E) Sxl and string

Accepted Answer

TAFs (TBP-associated factors) are basal transcription factors that associate with TBP (TATA-binding protein) to form the TFIID complex, which then binds to the TATA box of eukaryotic class II genes and assists in initiating transcription.

Question 18

Most decisions controlling the amount of gene product synthesized are made during
A) termination of replication.
B) transport of mRNA to the cytoplasm.
C) initiation of transcription.
D) alternative splicing.
E) regulation of translation.

Accepted Answer

Initiation of transcription is the stage at which most decisions controlling the amount of gene product synthesized are made, as it determines whether and how much of a particular mRNA is produced, directly influencing the amount of protein synthesized from that mRNA.

Question 19

A transcription factor that increases initiation of transcription by associating with an enhancer element is termed a(n)
A) initiator.
B) activator.
C) repressor.
D) enhancer.
E) super-repressor.

Accepted Answer

A transcription factor that increases initiation of transcription by associating with an enhancer element is called an activator. This is because it enhances the binding of RNA polymerase to the promoter region, leading to increased transcription. Initiators are proteins that bind to the TATA box, a DNA sequence found in the promoter region. Repressors are transcription factors that inhibit transcription by binding to the operator region, while enhancers are DNA sequences that can increase transcription by binding to transcription factors. A super-repressor is a mutant form of a repressor that binds to the operator region more strongly than the normal repressor, leading to even greater inhibition of transcription.

Question 20

The primary function of basal transcription factors is to
A) repress transcription initiation of a particular gene.
B) assist in associating RNA polymerase with the promoter element.
C) increase transcription by binding enhancer sequences.
D) activate RNA synthesis at origins of replication.
E) regulate activity of DNA polymerase II.

Accepted Answer

Basal transcription factors assist in the assembly of the preinitiation complex at the core promoter, which includes RNA polymerase, allowing for transcription initiation to occur. They do not repress transcription initiation, bind enhancer sequences, activate RNA synthesis at origins of replication, or regulate DNA polymerase II.

Quiz 10: Analyzing Genomic Variation

The gene products encoded by trans-acting elements perform their function by

In generating a reporter construct to study gene regulation,the reporter gene introduced replaces

Mutations introduced into reporter constructs are used to study

The __________________________ is the cis-acting DNA sequence that serves as the binding site for RNA polymerase.

Which of the following is not true of enhancer DNA sequences?

Which of these is most important to ChIP (chromatin immunoprecipitation) technology?

Zinc-finger peptide motifs are responsible for what aspect of protein function?

_______________ motifs function to promote the DNA-binding activity of many transcriptional activator proteins.

Mutations altering the amount of protein synthesized from a reporter construct occur most often in which of the following sequences of DNA?

Transcription in prokaryotes and eukaryotes is similar in that

Trans-acting proteins that influence transcription are commonly referred to as

RNA polymerase I synthesizes _________ using a DNA template.

A cis-acting DNA sequence that modulates the basal rate of transcription of a gene is termed a(n)

DNA sequences that serve as binding sites for proteins regulating transcription and are often found adjacent to a gene are said to be

______________ are cis-acting DNA sequences that often function at a distance from the gene they are regulating.

tRNA molecules are transcribed by

_____________ are basal transcription factors that associate with TBP to assist in initiating transcription from eukaryotic class II genes.

Most decisions controlling the amount of gene product synthesized are made during

A transcription factor that increases initiation of transcription by associating with an enhancer element is termed a(n)

The primary function of basal transcription factors is to