Question 1

Which of the following is NOT a required component for a standard polymerase chain reaction (PCR)?

Accepted Answer

Ribosomes

Question 2

During the PCR process, what is the primary purpose of the denaturation step?

Accepted Answer

To separate the DNA strands by breaking hydrogen bonds

Question 3

Which enzyme is used in reverse transcriptase PCR (RT-PCR) to generate cDNA from RNA?

Accepted Answer

Reverse transcriptase

Question 4

A researcher wants to determine if a specific gene contains an intron. Which experimental approach would best allow them to distinguish between genomic DNA (gDNA) and complementary DNA (cDNA) for this gene?

Accepted Answer

Compare PCR products amplified from gDNA and cDNA templates

Question 5

In Sanger sequencing, what is the role of dideoxynucleotides (ddNTPs)?

Accepted Answer

They terminate DNA strand elongation by lacking a 3' hydroxyl group

Question 6

Which of the following best describes the output of an automated Sanger sequencing reaction?

Accepted Answer

A series of colored peaks representing the order of nucleotides

Question 7

A PCR reaction is set up with the following components: template DNA, primers, dNTPs, and DNA polymerase. After 30 cycles, what is the theoretical amplification of the target DNA sequence?

Accepted Answer

$$2^{30}$$

Question 8

Which of the following statements about next-generation sequencing (NGS) is TRUE?

Accepted Answer

NGS can sequence entire genomes in parallel, producing large amounts of data quickly

Question 9

A patient is suspected of having a genetic disease caused by a single nucleotide mutation. Which molecular technique would be most appropriate for rapidly detecting this mutation?

Accepted Answer

PCR followed by DNA sequencing

Question 10

In a real-time PCR (qPCR) experiment, what is measured to determine the amount of DNA template present?

Accepted Answer

Fluorescence emitted by detector molecules

Question 11

Which of the following best explains why thermostable DNA polymerase is used in PCR?

Accepted Answer

It can withstand the high temperatures required for DNA denaturation

Question 12

A scientist is using PCR to amplify a gene of interest. Which step ensures that only the target region is amplified?

Accepted Answer

The use of primers complementary to sequences flanking the target region

Question 13

Which of the following is a direct application of DNA sequencing in medicine?

Accepted Answer

Identifying disease-causing mutations in patient genomes

Question 14

In the context of PCR, what is the function of oligonucleotide primers?

Accepted Answer

They provide a starting point for DNA synthesis by DNA polymerase

Question 15

A researcher is comparing the expression of a gene in two different cell types using RT-qPCR. What is the first step in this process?

Accepted Answer

Isolate RNA from the cells

Question 16

Which of the following best describes the chain termination method of DNA sequencing?

Accepted Answer

It uses ddNTPs to terminate DNA synthesis at specific nucleotides, generating fragments of varying lengths

Question 17

A PCR-based COVID-19 test uses which of the following techniques to detect viral RNA?

Accepted Answer

Reverse transcriptase PCR (RT-PCR) followed by quantitative PCR (qPCR)

Question 18

Why is it important to compare cDNA and genomic DNA (gDNA) sequences when studying gene structure?

Accepted Answer

To identify the presence of introns and alternatively spliced transcripts

Question 19

Which of the following is a major advantage of next-generation sequencing (NGS) over Sanger sequencing?

Accepted Answer

NGS can sequence millions of DNA fragments simultaneously, reducing time and cost

Question 20

A scientist wants to verify that a cloned DNA sequence does not contain any unintended mutations. Which technique should they use?

Accepted Answer

DNA sequencing of the cloned region

Molecular Techniques in Genetics: PCR and DNA Sequencing

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