Question 1

Which of the following is NOT a required component for a standard Polymerase Chain Reaction (PCR)?

Accepted Answer

Restriction enzymes

Question 2

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

Accepted Answer

To separate the DNA strands by heating

Question 3

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

Accepted Answer

Reverse transcriptase

Question 4

A researcher wants to compare the amount of a specific DNA sequence in two different tissue samples. Which PCR technique should they use?

Accepted Answer

Real-time PCR (qPCR)

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 thermostable DNA polymerase is essential for PCR?

Accepted Answer

It resists degradation at high temperatures used during denaturation

Question 7

A COVID-19 diagnostic test uses RT-qPCR. What is the sequence of steps in this test?

Accepted Answer

RNA extraction → Reverse transcription → Quantitative PCR

Question 8

Which of the following statements about gel electrophoresis is TRUE?

Accepted Answer

It separates DNA fragments based on their length

Question 9

Why is it important that PCR primers are complementary to sequences at the ends of the DNA fragment to be amplified?

Accepted Answer

To define the region of DNA that will be amplified

Question 10

A scientist is sequencing a gene using Sanger sequencing. If a ddATP is incorporated at a specific position, what will happen?

Accepted Answer

The DNA strand will terminate at that position

Question 11

Which of the following best describes the main advantage of automated DNA sequencing over manual methods?

Accepted Answer

It allows for faster and more accurate reading of DNA sequences

Question 12

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

Accepted Answer

Identifying genetic mutations associated with diseases

Question 13

If a PCR reaction fails to produce any product, which of the following is LEAST likely to be the cause?

Accepted Answer

Too much template DNA was added

Question 14

Which of the following equations correctly represents the exponential amplification of DNA in PCR after $$n$$ cycles, starting with a single DNA molecule?

Accepted Answer

$$N = 2^n$$

Question 15

A patient’s DNA is sequenced to identify a mutation causing a genetic disorder. Which step in Sanger sequencing ensures that fragments of all possible lengths are generated?

Accepted Answer

Using a mixture of dNTPs and ddNTPs

Question 16

Which of the following best explains why dideoxynucleotides (ddNTPs) terminate DNA synthesis in Sanger sequencing?

Accepted Answer

They lack a 3' hydroxyl group

Question 17

In a real-time PCR (qPCR) experiment, what does an increase in fluorescence indicate?

Accepted Answer

Synthesis of new DNA

Question 18

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

Accepted Answer

dNTPs have a 3' hydroxyl group, ddNTPs do not

Question 19

A forensic scientist is analyzing a crime scene sample using PCR. Why is it important to use primers specific to human DNA?

Accepted Answer

To ensure only human DNA is amplified, avoiding contamination from other organisms

Question 20

Which of the following best describes the relationship between PCR and DNA sequencing?

Accepted Answer

PCR amplifies DNA, providing enough material for sequencing

Molecular Techniques in Genetics: PCR and DNA Sequencing

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