GRE Subject Test: Biochemistry, Cell, and Molecular Biology : Help with Transcription Processes

Study concepts, example questions & explanations for GRE Subject Test: Biochemistry, Cell, and Molecular Biology

varsity tutors app store varsity tutors android store

All GRE Subject Test: Biochemistry, Cell, and Molecular Biology Resources

1 Diagnostic Test 201 Practice Tests Question of the Day Flashcards Learn by Concept

Example Questions

Example Question #1 : Help With Transcription Processes

What is the role of the promoter region in the regulation of gene expression?

Possible Answers:

Bind negative regulators to inhibit gene expression

Recruit RNA polymerase and transcription factors to DNA

Allow for alternative splicing and recombination of genetic components

Alter gene expression by binding transcription factors

Correct answer:

Recruit RNA polymerase and transcription factors to DNA

Explanation:

The promoter region is the site of a gene where RNA polymerase and other transcription factors bind to DNA, upstream from the gene locus. A mutation in this region commonly results in a decrease in the amount of gene transcribed.

An enhancer region is a stretch of DNA that alters gene expression by binding transcription factors, while a silencer region is a site on the gene where repressor proteins bind. Introns are intervening non-coding segments of DNA that are not expressed in the final protein. Alternative splicing patterns of introns and exons allows for multiple proteins to be generated from a single gene.

Example Question #2 : Help With Transcription Processes

Which of the following are methods for termination of transcription in prokaryotes?

I. Release factor binding

II. Rho-mediated termination

III. Hairpin loop (stem loop) formation

Possible Answers:

I, II, and III

III only

II and III

I only

Correct answer:

II and III

Explanation:

The binding of release factors is a common way to terminate translation, not transcription.

Rho-mediated termination and hairpin loop formation are both common ways to terminate prokaryotic transcription. The formation of the hairpin loop disrupts the transcription machinery and the DNA-RNA interactions, which allows termination of transcription. Rho is a protein that is capable of binding single-stranded RNA and terminating transcription. 

Example Question #3 : Help With Transcription Processes

What event is indicative of transcription initiation?

Possible Answers:

Telomerase lengthens the telomeres of the DNA

RNA polymerase is removed from the DNA

The RNA strand begins to be synthesized

RNA polymerase binds to the promoter

Correct answer:

RNA polymerase binds to the promoter

Explanation:

During the initiation of transcription, RNA polymerase and a group of transcription factors bind to the promoter for a given gene. This DNA segment signals the RNA polymerase where to begin creating the RNA strand. 

Example Question #4 : Help With Transcription Processes

Which of the following best describes distant regulatory sequences that influence gene expression?

Possible Answers:

Transcriptional start sites

Enhancers

Exons

Introns

Promoters

Correct answer:

Enhancers

Explanation:

The correct answer is enhancer. Transcription factors and mediators bind enhancer regions of DNA and influence the transcription of distant genes by chromatin looping to the proximal promoter. Promoters are regulatory sequences, however, they are typically 2 kilobase pairs upstream of the gene for which they influence transcription. Introns and exons make up a gene and are the non-coding and coding regions of the gene, respectively. The transcriptional start site consists of the first few nucleotides that are transcribed into an mRNA sequence from a gene, usually containing the 5' untranslated region (UTR).  

Example Question #5 : Help With Transcription Processes

When does alternative splicing occur? 

Possible Answers:

Following mRNA translocation to the cytosol 

Following mRNA loading into ribosome

Following mRNA polyadenylation 

Following pre-mRNA transcription in the nucleus

Following translation

Correct answer:

Following pre-mRNA transcription in the nucleus

Explanation:

The correct answer is following pre-mRNA transcription in the nucleus. Pre-mRNA contains introns and exons. Following transcription, splicing and alternative splicing occurs to remove introns and select exons, respectively, by the spliceosome. Following splicing, 3' poly adenylation and 5' capping occur to generate a mature mRNA transcript that will translocate to the cytosol and be translated by ribosomes. 

Example Question #6 : Help With Transcription Processes

What element(s) do all eukaryotic promoter regions share?

Possible Answers:

None of these

All of these

A basal promoter (TATA box)

Transcription factors

Enhancers that accept binding agents

Correct answer:

All of these

Explanation:

Eukaryotic promoters share basic, highly conserved structure. This area does not evolve quickly because it is extremely important in DNA transcription. These promoters (in most cases) include a basic basal promoter like a TATA box, and enhancers that bind to transcription factors.

Example Question #7 : Help With Transcription Processes

During transcription of a eukaryotic cell, what determines the template strand?

Possible Answers:

The base sequence of the promoter

The location of the MET start codon

The base sequence of the operator

The location of the AUG start codon

The base sequence of the enhancer

Correct answer:

The base sequence of the promoter

Explanation:

The TATA box is found in the promoter region of the template strand. This TATA box serves as a signal for the initiation of translation of DNA into mRNA. The location of the promoter region and it's unique base sequence signals the start of the translation process.

All GRE Subject Test: Biochemistry, Cell, and Molecular Biology Resources

1 Diagnostic Test 201 Practice Tests Question of the Day Flashcards Learn by Concept
Learning Tools by Varsity Tutors

Incompatible Browser

Please upgrade or download one of the following browsers to use Instant Tutoring: