Question 1

Which of the following best describes the role of specific transcription factors in gene expression?

Accepted Answer

They bind to non-coding regulatory DNA sequences to activate or repress transcription.

Question 2

Transcription factors are encoded by which type of DNA sequence?

Accepted Answer

Coding DNA sequences

Question 3

Which of the following statements about the interaction between transcription factors and DNA is accurate?

Accepted Answer

Amino acid residues in the DNA binding domain of transcription factors form hydrogen bonds with specific DNA base pairs.

Question 4

A mutation in the core promoter region of a gene is most likely to affect which process?

Accepted Answer

Recruitment of general transcription factors and RNA polymerase

Question 5

Which of the following best explains why a frameshift mutation can have a more severe effect on protein function than a missense mutation?

Accepted Answer

A frameshift mutation alters the reading frame, changing all downstream amino acids.

Question 6

A single base pair substitution in the coding region of the beta-globin gene changes a codon from GAG (Glu) to GTG (Val). What type of mutation is this, and what disease is it associated with?

Accepted Answer

Missense mutation; sickle cell disease

Question 7

Which of the following is a likely consequence of a two base pair insertion within the coding region of a gene?

Accepted Answer

A frameshift mutation that disrupts the production of a functional protein

Question 8

General transcription factors primarily bind to which region of a gene?

Accepted Answer

Core promoter

Question 9

A mutation in a non-coding regulatory element that creates a new binding site for a transcription factor could result in which of the following?

Accepted Answer

Altered gene expression due to inappropriate activation or repression

Question 10

Which of the following best describes the function of an enhancer element in eukaryotic gene regulation?

Accepted Answer

It increases transcription by serving as a binding site for specific transcription factors.

Question 11

A mutation in the non-coding region of DNA that does NOT affect a transcription factor binding site is most likely to:

Accepted Answer

Have no impact on gene expression

Question 12

Which of the following is TRUE regarding the bonds formed between transcription factors and DNA?

Accepted Answer

They are non-covalent and reversible, allowing transient interactions.

Question 13

A silent mutation is best defined as:

Accepted Answer

A change in the DNA sequence that does not alter the amino acid sequence of the protein.

Question 14

Which of the following scenarios would most likely result in a nonsense mutation?

Accepted Answer

A single base pair substitution that changes a codon to a stop codon

Question 15

If a mutation occurs in the TATA box of a core promoter, what is the most likely effect?

Accepted Answer

Reduced or abolished transcription initiation

Question 16

Which of the following best explains why mutations in non-coding regulatory elements can have significant effects on gene expression?

Accepted Answer

They can disrupt or create binding sites for transcription factors, altering transcription levels.

Question 17

A patient is found to have a small deletion in the coding region of a gene, but the amino acid sequence of the protein is unchanged. What type of mutation is this?

Accepted Answer

Silent mutation

Question 18

Which of the following is a direct result of a missense mutation in a gene's coding region?

Accepted Answer

A single amino acid in the protein is changed to a different amino acid.

Question 19

Which of the following best describes combinatorial regulation of gene expression?

Accepted Answer

Multiple transcription factors bind to different regulatory elements to fine-tune gene expression.

Question 20

A mutation in the enhancer region of a gene reduces the binding affinity of a specific transcription factor. What is the most likely outcome?

Accepted Answer

Decreased transcription of the gene

Transcription Factors and Gene Regulation: Coding vs. Non-Coding DNA

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