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 double-stranded DNA into single strands

Question 3

Which equation best represents the theoretical amplification of DNA after $$n$$ cycles of PCR, starting with a single DNA molecule?

Accepted Answer

$$2^n$$

Question 4

A researcher wants to quantify the amount of a specific mRNA in a cell sample. Which PCR variation should they use?

Accepted Answer

Reverse transcriptase PCR (RT-PCR)

Question 5

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

Accepted Answer

They terminate DNA strand elongation

Question 6

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

Accepted Answer

It is not affected by the high temperatures used during denaturation

Question 7

A scientist is using real-time PCR (qPCR) to compare the amount of DNA template in two samples. What feature of qPCR allows for this comparison?

Accepted Answer

The measurement of fluorescence during each cycle

Question 8

Which of the following statements about gel electrophoresis is correct?

Accepted Answer

It separates DNA fragments based on their length

Question 9

In a Sanger sequencing reaction, what would happen if only dNTPs and no ddNTPs were included?

Accepted Answer

Only full-length DNA strands would be produced

Question 10

A patient is suspected of having a genetic disease caused by a single nucleotide mutation. Which molecular technique would be most appropriate to confirm the presence of this mutation?

Accepted Answer

DNA sequencing

Question 11

Which of the following best describes the function of oligonucleotide primers in PCR?

Accepted Answer

They provide a starting point for DNA polymerase to extend the DNA strand

Question 12

Why is it important that ddNTPs used in Sanger sequencing lack a 3' hydroxyl group?

Accepted Answer

It causes chain termination during DNA synthesis

Question 13

A forensic scientist is analyzing a crime scene sample using PCR. Which step ensures that only the region of interest is amplified?

Accepted Answer

The design of primers complementary to sequences flanking the region of interest

Question 14

Which of the following is a real-world application of DNA sequencing?

Accepted Answer

Identifying the species of an unknown organism

Question 15

In a PCR reaction, what would be the likely result if the primers were not complementary to the target DNA sequence?

Accepted Answer

No amplification of the target DNA

Question 16

Which of the following best explains why PCR is a powerful tool in molecular biology?

Accepted Answer

It can amplify specific DNA sequences from very small amounts of starting material

Question 17

A COVID-19 diagnostic test uses RT-qPCR. What is the main advantage of this method for viral detection?

Accepted Answer

It can quantify viral RNA in real time

Question 18

Which of the following is a critical difference between dNTPs and ddNTPs used in DNA sequencing?

Accepted Answer

ddNTPs lack a 3' hydroxyl group, preventing further elongation

Question 19

A researcher is comparing the DNA sequences of two related species to study their evolutionary relationship. Which technique is most appropriate for this analysis?

Accepted Answer

DNA sequencing followed by sequence alignment

Question 20

Which of the following best describes the output of an automated DNA sequencing machine?

Accepted Answer

A series of colored peaks representing the order of nucleotides

Molecular Techniques in Genetics: PCR and DNA Sequencing

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