Learn Smart PKA- Chapter Fourteen: Gene Expression at the Molecular Level III: Gene Regulation

How do activators and repressors regulate the function of RNA polymerase in eukaryotes? Activators and repressors bind to the TATA box and recruit RNA polymerase. Activators and repressors interact with GTFs or mediator proteins. Activators and repressors determine the transcriptional start site.

Activators and repressors interact with GTFs or mediator proteins.

Which of the following is a form of gene regulation in which a eukaryotic pre-mRNA can be processed to produce more than one mature RNA? DNA splicing Genetic recombination Alternative genetic code Exon splicing Alternative splicing

Alternative splicing

What is the advantage of operon organization in bacteria? Bacteria can synthesize all of their amino acids. Bacteria can coordinate the expression of multiple genes in the same biological pathway. Bacteria do not need transcriptional regulatory factors to control gene expression. Bacteria can metabolize numerous types of sugar molecules.

Bacteria can coordinate the expression of multiple genes in the same biological pathway.

Most eukaryotic genes, particularly those found in multicellular species, are regulated by many different factors. This phenomenon is called _______ control.

combinatorial or combinational

DNA methylation may prevent transcription by blocking a(n) ______ site or by converting ______ to a closed conformation. terminator ; RNA pol enhancer ; RNA pol enhancer ; chromatin terminator ; chromatin

enhancer ; chromatin

The plant Arabidopsis thaliana has more than _______ different genes which encode proteins that regulate the transcription of other genes. 1,500 500 5,000 2,500

1,500

What is the organization of the genes in the lac operon, starting from the lac regulatory gene (lacI) and ending with the lac terminator? Place the DNA element nearest to lacI on top. lacZ lacA lacP (promoter) lacY lacO (operator)

1. lacP (promoter) 2. lacO (operator) 3. lacZ 4. lacY 5. lacA

The importance of gene regulation is underscored by the number of genes devoted to this process in an organism. For example, in the plant Arabidopsis thaliana, over _______ of its genome is involved with regulating gene transcription. 15% 5% 10% 20%

5%

Which of the following are key differences between eukaryotic and prokaryotic transcriptional regulation? Combinatorial control of gene expression is more common in eukaryotes. The complexity of eukaryotic development requires that transcription be more coordinated and integrated than in prokaryotes. Activator and repressor proteins influence the ability of RNA polymerase to bind to DNA only in prokaryotic transcription. The majority of genes are organized individually in eukaryotes, but are organized as operons in prokaryotes.

Combinatorial control of gene expression is more common in eukaryotes.The complexity of eukaryotic development requires that transcription be more coordinated and integrated than in prokaryotes.The majority of genes are organized individually in eukaryotes, but are organized as operons in prokaryotes.

Which of the following accurately describe the role of chromatin packing in the expression of eukaryotic genes? Loosely packed chromatin allows transcription factors and RNA polymerase to access the promoter site and transcription can take place. When chromatin is in the closed conformation it is easily transcribed; but when in the open conformation transcription cannot take place. Three-dimensional chromatin packaging has no effect on transcription. Tightly packed chromatin is difficult to transcribe.

Loosely packed chromatin allows transcription factors and RNA polymerase to access the promoter site and transcription can take place. Tightly packed chromatin is difficult to transcribe.

The lac operon shown here depicts which of the following environments? Low glucose and low lactose High glucose and high lactose High glucose and low lactose Low glucose and high lactose

Low glucose and high lactose

How can DNA methylation inhibit transcription? Methylation can increase the affinity of RNA polymerase for promoter sequences. Methylation can convert DNA from an open conformation to a closed one. Methylation can recruit additional histones to DNA. Methylation can prevent an activator from binding to an enhancer.

Methylation can convert DNA from an open conformation to a closed one. Methylation can prevent an activator from binding to an enhancer.

How can DNA methylation inhibit transcription? Methylation can prevent an activator from binding to an enhancer. Methylation can increase the affinity of RNA polymerase for promoter sequences. Methylation can convert DNA from an open conformation to a closed one. Methylation can recruit additional histones to DNA.

Methylation can prevent an activator from binding to an enhancer. Methylation can convert DNA from an open conformation to a closed one.

What are regulatory transcription factors? Proteins that bind to DNA and affect the transcription of one or more genes Small molecules that regulate the synthesis of proteins from mRNA Proteins that synthesize RNA from a DNA template Small molecules that influence the ability of repressor proteins to bind to DNA

Proteins that bind to DNA and affect the transcription of one or more genes

What are regulatory transcription factors? Proteins that synthesize RNA from a DNA template Small molecules that regulate the synthesis of proteins from mRNA Small molecules that influence the ability of repressor proteins to bind to DNA Proteins that bind to DNA and affect the transcription of one or more genes

Proteins that bind to DNA and affect the transcription of one or more genes

Eukaryotic gene expression can be regulated at which levels? RNA modification transcription transformation replication translation

RNA modification translation transcription

Why are interactions between RNA polymerase II and GTFs important for transcription in eukaryotes? Interactions between RNA polymerase and GTFs increase the rate of transcription because GTFs act as enhancers. RNA polymerase II and GTFs must interact for the polymerase to bind properly at the core promoter site of the DNA. RNA polymerase II must bind to GTFs in order for the elongation step of transcription.

RNA polymerase II and GTFs must interact for the polymerase to bind properly at the core promoter site of the DNA.

Match each protein or group of proteins with its role in transcription. RNA polymerase RNA polymerase drop zone empty. general transcription factors general transcription factors drop zone empty. activators

RNA polymerase- synthesis of RNA from a DNA template general transcription factors matches- required for binding to the core promoter and initiating transcription activators- binding to enhancer sequences and interaction with other proteins

Which of the following best describes the organization of sequences in a typical eukaryotic promoter? Transcriptional start site — Regulatory elements — TATA box —Structural gene TATA box — Regulatory elements — Transcriptional start site —Structural gene Regulatory elements — Transcriptional start site — TATA box —Structural gene Regulatory elements — TATA box — Transcriptional start site — Structural gene Transcriptional start site — TATA box — Regulatory elements —Structural gene

Regulatory elements — TATA box — Transcriptional start site — Structural gene

What is the role of small effector molecules in transcriptional control? Small effector molecules bind to transcription regulatory factors and alter how they bind to DNA. Small effector molecules change the permeability of the plasma membrane so that transcription factors can enter the cell. Small effector molecules bind directly to the DNA and are involved in either positive or negative control. Small effector molecules bind to mRNA and regulate its ability to be converted into protein

Small effector molecules bind to transcription regulatory factors and alter how they bind to DNA.

The process whereby different transcripts are made from a single gene is called

alternative splicing

In many multicellular species a combination of many different factors determines the regulation of gene expression. This is called: eukaryotic control complex transcription genetic recombination combinatorial control

combinatorial control

Operons enable bacteria to: regulate gene expression after transcription has occurred coordinate the regulation of genes with related functions produce several alternate mRNAs from the same gene synthesize their own amino acids

coordinate the regulation of genes with related functions

This figure shows the appearance of the lac operon in environments with: low glucose and low lactose low glucose and high lactose high glucose and high lactose high glucose and low lactose

high glucose and high lactose

When and where might alternatively spliced gene products occur? when the pre-mRNA transcript is longer than normal in different tissues in an animal in different cells with CpG methylation during different stages in animal development

in different tissues in an animal during different stages in animal development

In mammals, when iron levels are high, iron binds to the iron regulatory protein, which results in: decreased transcription of ferritin increased translation of ferritin decreased translation of ferritin increased transcription of ferritin

increased translation of ferritin

In E. coli, the lac operon is ______ in the presence of lactose, and the trp operon is ______ in the presence of tryptophan. repressed; induced induced; repressed repressed; repressed induced; induced

induced; repressed

The following diagram shows the: lac operon in the presence of lactose trp operon in the presence of tryptophan trp operon in the absence of tryptophan lac operon in the absence of lactose

lac operon in the absence of lactose

This diagram is a representation of the: trp operon in the presence of tryptophan lac operon in the absence of lactose trp operon in the absence of tryptophan lac operon in the presence of lactose

lac operon in the presence of lactose

Which of the following represents the correct order of DNA segments in the lac operon? lacP - lacA - lacZ - lacY - lacO lacZ - lacP - lacO - lacY - lacA lacO - lacP - lacZ - lacA - lacY lacO - lacP - lacZ - lacY - lacA lacP - lacO - lacZ - lacY - lacA

lacP - lacO - lacZ - lacY - lacA

Bacteria and eukaryotes can regulate genes at the level of transcription. In eukaryotes, gene expression is also commonly regulated at the levels of RNA ________ and translation.

modification

Regulatory transcription factors influence the expression of genes by binding directly to DNA at or near the _________ site and affect the rate of transcription.

promoter

An advantage of alternative splicing is that it increases the size of the ______ while minimizing the size of the ______. proteome ; transcriptome genome ; proteome genome ; transcriptome proteome ; genome

proteome ; genome

The genes in the trp operon encode enzymes that make the amino acid ________.

tryptophan

What are the three features common to most promoters that are needed for the initiation of transcription of protein coding genes in eukaryotes? Pre-initiation complex TATA box Transcriptional start site AUG start codon Regulatory elements

TATA box Transcriptional start site Regulatory elements

The most common organization of sequences for the promoter of eukaryotic structural genes is the regulatory elements, ______ box and ________ start site.

TATA box Transcriptional start site

In order for transcription of protein coding genes in eukaryotes to begin, the promoter must have several key features. What are they? RNA polymerase, TATA box, enhancers Core promoter, RNA polymerase, TATA box Promoter, operator, CAP site TATA box, regulatory elements, transcriptional start site

TATA box, regulatory elements, transcriptional start site

Which is a result of alternative splicing? The cell spends more energy replicating DNA. The proteome size is increased and the genome size is minimized. Mutations occur less frequently. The genome size is increased and the proteome size is minimized.

The proteome size is increased and the genome size is minimized.

What is the function of the genes encoded by the trp operon? The synthesis of the amino acid tryptophan The transport of the amino acid tryptophan into the cell The breakdown of the amino acid tryptophan The incorporation of the amino acid tryptophan into cellular proteins

The synthesis of the amino acid tryptophan

What is the function of the genes encoded by the trp operon? The transport of the amino acid tryptophan into the cell The synthesis of the amino acid tryptophan The breakdown of the amino acid tryptophan The incorporation of the amino acid tryptophan into cellular proteins

The synthesis of the amino acid tryptophan

Which of the following accurately describe the role of chromatin packing in the expression of eukaryotic genes? Tightly packed chromatin is difficult to transcribe. When chromatin is in the closed conformation it is easily transcribed; but when in the open conformation transcription cannot take place. Loosely packed chromatin allows transcription factors and RNA polymerase to access the promoter site and transcription can take place. Three-dimensional chromatin packaging has no effect on transcription.

Tightly packed chromatin is difficult to transcribe. Loosely packed chromatin allows transcription factors and RNA polymerase to access the promoter site and transcription can take place.

What is the difference between levels of transcription of chromatin in the open versus closed conformation? Transcription is low when in the open conformation and high when in the closed conformation. Transcription levels are high in both the open and closed conformations. Transcription levels are low in both the open and closed conformations. Transcription is high when in the open conformation and low when in the closed conformation.

Transcription is high when in the open conformation and low when in the closed conformation.

What is the first nucleotide that is transcribed called? Start codon Transcriptional start site Basal transcription site TATA box Preinitiation complex site

Transcriptional start site

Small effector molecules are involved in gene regulation. Proteins influence the ability of RNA polymerase to bind to the DNA.

Which of the following are similarities between eukaryotic and prokaryotic transcriptional regulation? Transcriptional control is a simple process that requires few steps. Small effector molecules are involved in gene regulation. Proteins influence the ability of RNA polymerase to bind to the DNA. Genes are organized into operons.

What are regulatory transcription factors? Small molecules that influence the ability of repressor proteins to bind to DNA Proteins that bind to DNA and affect the transcription of one or more genes Proteins that synthesize RNA from a DNA template Small molecules that regulate the synthesis of proteins from mRNA

Which of the following are similarities between eukaryotic and prokaryotic transcriptional regulation? Transcriptional control is a simple process that requires few steps. Small effector molecules are involved in gene regulation. Proteins influence the ability of RNA polymerase to bind to the DNA. Genes are organized into operons.

The lac repressor binds to the lac operon when lactose is ______, and the trp repressor binds to the trp operon when tryptophan is ______. present; present absent; absent present; absent absent; present

absent; present

Small effector molecules exert their effects by binding to two types of regulatory transcription factors: _______ and _______. This binding causes conformational changes in these proteins that affect their ability to bind to DNA.

activators repressors

In muscle cells, one protein might be composed of exons 1, 2, 5, 6, and 7 of a particular mRNA, while in brain cells, the protein made from the same mRNA consists of exons 1, 2, 4, 6, 7, and 8. This is an example of a form of gene regulation called

alternative splicing

What molecules can influence transcription by binding to enhancers or silencers? repressors and activators mediators and coactivators general transcription factors RNA polymerase II and III

repressors and activators

The transcriptional start site contains: general transcription factors the TATA box the binding site for the mediator protein complex the first base that is transcribed the starting amino acid in the protein

the first base that is transcribed

The transcriptional start site contains: the starting amino acid in the protein general transcription factors the binding site for the mediator protein complex the first base that is transcribed the TATA box

the first base that is transcribed

In mammals, iron toxicity is prevented by regulating the ______ of ferritin. replication translation splicing transcription iron content

translation