Gene Expression: The Control Center of Cells

Question 1

Regulatory elements that can control gene expression do NOT include:

Accepted Answer

Exons

Answer

Transcription factors

Answer

Enhancers

Answer

Silencers

Question 2

In eukaryotes, gene regulation occurs at multiple levels, excluding:

Accepted Answer

DNA replication

Answer

Translation

Question 3

A gene essential for cell survival may be regulated by:

Accepted Answer

A combination of enhancers, silencers, and transcription factors

Answer

Weak silencers

Question 4

How can environmental factors affect gene expression?

Accepted Answer

By all of the following: altering transcription factor binding affinity, modifying chromatin structure, influencing mRNA stability

Answer

By modifying chromatin structure

Question 5

Dysregulated gene expression can potentially lead to:

Accepted Answer

All of the following: cancer, neurodegenerative diseases, developmental abnormalities

Answer

Neurodegenerative diseases

Question 6

Which of the following is NOT a key function of transcription factors in gene expression?

Accepted Answer

Modifying DNA methylation patterns

Answer

Binding to specific DNA sequences

Answer

Activating or repressing gene transcription

Answer

Recruiting RNA polymerase to the promoter

Question 7

Enhancers are regulatory DNA sequences that:

Accepted Answer

Promote gene expression by enhancing the binding of transcription factors

Answer

Inhibit gene expression by blocking the binding of transcription factors

Answer

Are exclusively found in prokaryotic cells

Answer

Are always located within introns

Question 8

Silencers are regulatory elements that:

Accepted Answer

Prevent the binding of RNA polymerase to the promoter

Answer

Attract transcription factors to the promoter

Answer

Are only found in prokaryotic cells

Answer

Are always located within exons

Question 9

What is the primary role of RNA polymerase in gene expression?

Accepted Answer

To synthesize RNA copies of genes

Answer

To modify histones

Answer

To bind to enhancers

Answer

To activate silencers

Question 10

Which of the following is not considered a regulatory element involved in gene expression?

Accepted Answer

Centromere

Answer

Enhancer

Answer

Promoter

Answer

Transcription factor

Question 11

What is the primary role of RNA polymerase in gene expression?

Accepted Answer

To attach to the promoter and initiate transcription

Answer

To synthesize proteins from mRNA

Answer

To remove introns from pre-mRNA

Answer

To modify histones to regulate gene expression

Question 12

Which modification to histones is associated with gene activation?

Accepted Answer

Acetylation of lysine 27

Answer

Methylation of lysine 9

Answer

Phosphorylation of serine 10

Answer

Ubiquitination of lysine 4

Question 13

What is the primary function of microRNAs in gene expression?

Accepted Answer

To cleave mRNA and inhibit its translation

Answer

To bind to mRNA and promote its translation

Answer

To modify histones to regulate gene expression

Answer

To amplify gene expression by increasing transcription

Question 14

Which of the following best describes a positive feedback loop in gene expression?

Accepted Answer

Activation of a gene that produces a transcription factor that activates itself

Answer

Production of a hormone that inhibits its own secretion

Answer

Degradation of a protein that inhibits its own synthesis

Answer

Synthesis of an enzyme that catalyzes its own production

Question 15

What is the key difference between constitutive and inducible genes?

Accepted Answer

Constitutive genes are always expressed, while inducible genes are expressed only when needed

Answer

Inducible genes are always expressed, while constitutive genes are expressed only when needed

Answer

Both constitutive and inducible genes are expressed only when needed

Answer

Both constitutive and inducible genes are always expressed

Question 16

What is the main significance of alternative splicing in gene expression?

Accepted Answer

It allows for the production of multiple proteins from a single gene

Answer

It regulates the stability of mRNA transcripts

Answer

It modifies the amino acid sequence of proteins

Answer

It prevents the translation of mRNA transcripts

Question 17

The process of copying a gene into mRNA is known as:

Accepted Answer

Transcription (correct)

Answer

Translation

Answer

Replication

Answer

Mutation

Question 18

Which of the following is a type of RNA molecule that carries amino acids to the ribosome?

Accepted Answer

tRNA (correct)

Answer

mRNA

Answer

rRNA

Answer

snRNA

Question 19

The process of producing a polypeptide chain from an mRNA molecule is known as:

Accepted Answer

Translation (correct)

Answer

Transcription

Answer

Replication

Answer

Mutation

Question 20

Which of the following is a role of transcription factors?

Accepted Answer

Regulating gene expression (correct)

Answer

Binding to specific DNA sequences

Answer

Processing RNA transcripts

Answer

Modifying chromatin structure

Question 21

Enhancers are DNA elements that:

Accepted Answer

Increase gene transcription (correct)

Answer

Decrease gene transcription

Answer

Block gene transcription

Answer

Do not affect gene transcription

Question 22

Silencers are DNA elements that:

Accepted Answer

Block gene transcription (correct)

Answer

Increase gene transcription

Answer

Decrease gene transcription

Answer

Do not affect gene transcription

Question 23

In eukaryotes, which of these elements regulate gene expression?

Accepted Answer

Transcription factors

Accepted Answer

Enhancers

Accepted Answer

Silencers

Answer

Operons

Question 24

Which regulatory element is NOT involved in controlling gene expression?

Accepted Answer

Ribosome

Answer

Transcription factor

Answer

Promoter

Answer

Enhancer

Question 25

Which of the following is an example of a post-transcriptional regulation mechanism?

Accepted Answer

Alternative splicing

Answer

Histone methylation

Answer

Promoter methylation

Answer

Translation initiation

Question 26

Which step initiates gene expression?

Accepted Answer

Transcription

Answer

Translation

Answer

RNA splicing

Answer

Protein folding

Question 27

What is the primary function of transcription factors?

Accepted Answer

To bind to specific DNA sequences and regulate transcription initiation.

Answer

To translate mRNA into amino acids.

Answer

To remove introns from RNA.

Answer

To assemble ribosomes.

Question 28

What is the process that modifies the primary mRNA transcript to remove introns and join exons?

Accepted Answer

RNA splicing

Answer

RNA editing

Answer

Translation

Answer

Post-translational modification

Question 29

Which technique is commonly used to study gene expression?

Accepted Answer

Microarray analysis

Answer

Gel electrophoresis

Answer

PCR

Answer

Immunohistochemistry

Question 30

Which of the following is a non-coding RNA involved in gene expression regulation?

Accepted Answer

MicroRNA

Answer

Transfer RNA

Answer

Ribosomal RNA

Answer

Messenger RNA

Question 31

How does gene expression contribute to cellular differentiation?

Accepted Answer

By controlling the synthesis of specific proteins in different cell types.

Answer

By modifying the structure of the cell membrane.

Answer

By regulating the cell division rate.

Answer

By altering the cell's metabolism.

Question 32

What is the primary function of transcription factors in gene expression?

Accepted Answer

To bind to specific DNA sequences and initiate transcription

Answer

To modify histones to make DNA more accessible

Answer

To terminate transcription

Answer

To edit mRNA transcripts before translation

Question 33

Which of the following epigenetic modifications is associated with increased gene expression?

Accepted Answer

Acetylation of histones

Answer

Methylation of cytosine residues in DNA

Answer

Phosphorylation of histones

Answer

Deacetylation of histones

Question 34

What is the role of enhancers in regulating gene expression?

Accepted Answer

To enhance the binding of transcription factors to promoters

Answer

To block the binding of transcription factors to promoters

Answer

To terminate transcription

Answer

To splice mRNA transcripts

Question 35

How does alternative splicing create a variety of proteins from a single gene?

Accepted Answer

Different combinations of exons are spliced together to produce different proteins.

Answer

Alternative splicing only happens in eukaryotic genes.

Answer

Alternative splicing is a completely random process.

Answer

Alternative splicing has no impact on the protein's overall function.

Question 36

What is the primary function of a transcription factor?

Accepted Answer

To regulate gene expression by binding to specific DNA sequences

Answer

To catalyze the synthesis of RNA

Answer

To cleave the sugar-phosphate backbone of DNA

Question 37

Which of the following is an example of a post-transcriptional modification of RNA?

Accepted Answer

Splicing

Answer

Translation elongation

Answer

DNA replication

Answer

Transcription initiation

Question 38

What is the primary function of enhancers in gene expression?

Accepted Answer

To increase the rate of transcription initiation by binding to transcription factors and RNA polymerase

Answer

To bind directly to RNA polymerase

Answer

To decrease the rate of transcription initiation

Question 39

Which of the following is a mechanism of gene silencing?

Accepted Answer

RNA interference

Answer

Translation elongation

Answer

Transcription activation

Question 40

What is the purpose of the genetic code?

Accepted Answer

To guide the translation of mRNA into a specific sequence of amino acids to build proteins

Answer

To regulate gene expression

Answer

To store genetic information

Question 41

What is the process of converting a gene into messenger RNA (mRNA)?

Accepted Answer

Transcription

Answer

Translation

Answer

Replication

Answer

Mutation

Question 42

What is the primary function of ribosomes in gene expression?

Accepted Answer

To provide the site for protein synthesis by catalyzing the formation of peptide bonds

Answer

To transcribe DNA into RNA

Answer

To cleave mRNA molecules

Answer

To regulate gene expression

Question 43

Which of the following activities is NOT involved in the role of RNA polymerase in gene expression?

Accepted Answer

Translation

Answer

Transcription initiation

Answer

RNA elongation

Answer

Promoter binding

Question 44

How do enhancers contribute to gene expression?

Accepted Answer

Bind transcription factors and facilitate their interaction with the promoter

Answer

Block promoter recognition by transcription factors

Answer

Synthesize RNA molecules directly

Question 45

Which type of RNA molecule carries the genetic information from DNA to the ribosomes for protein synthesis?

Accepted Answer

Messenger RNA (mRNA)

Answer

Ribosomal RNA (rRNA)

Answer

Transfer RNA (tRNA)

Answer

MicroRNA (miRNA)

Question 46

What is the significance of introns and exons in gene expression?

Accepted Answer

Introns are removed during splicing to produce mature mRNA, which codes for proteins

Answer

Introns carry the genetic code for proteins

Answer

Exons are spliced out during translation

Question 47

How do silencers regulate gene expression?

Accepted Answer

Bind transcription factors and inhibit their interaction with the promoter

Answer

Modify histones to enhance chromatin accessibility

Answer

Activate transcription factors to promote gene transcription

Question 48

What is the primary purpose of alternative splicing?

Accepted Answer

To generate different protein isoforms from a single gene

Answer

To eliminate non-coding sequences from mRNA transcripts

Answer

To enhance mRNA stability and prevent degradation

Question 49

What is a key application of gene expression profiling?

Accepted Answer

To identify genes associated with specific diseases or biological processes

Answer

To determine the order and arrangement of genes on chromosomes

Answer

To predict protein function based on gene sequences

Question 50

Which technique is commonly utilized to analyze patterns of gene expression?

Accepted Answer

Microarray

Answer

Polymerase chain reaction (PCR)

Answer

Agarose gel electrophoresis

Answer

High-performance liquid chromatography (HPLC)