DNA Sequencing: Principles and Applications in Molecular Biology

Question 1

For high-throughput DNA sequencing of large genomes or populations, which technique is commonly employed?

Accepted Answer

Next-Generation Sequencing (NGS)

Answer

Sanger sequencing

Answer

Pyrosequencing

Question 2

The principle underlying Sanger sequencing involves:

Accepted Answer

Chain termination of DNA synthesis using dideoxynucleotides

Answer

PCR amplification of a specific DNA fragment

Answer

Quantitative analysis of DNA fragments based on size

Answer

Detection of specific DNA sequences using hybridization probes

Question 3

In next-generation sequencing (NGS), the fluorescence detector primarily determines:

Accepted Answer

The intensity of fluorescently tagged nucleotides

Answer

The length of DNA fragments

Answer

DNA sequences using labeled primers

Answer

The separation of DNA fragments by length

Question 4

Bioinformatics plays a vital role in DNA sequencing by:

Accepted Answer

Processing and interpreting raw sequencing data

Answer

Designing primers for DNA amplification

Answer

Detecting and correcting sequencing errors

Answer

Providing genetic counseling services

Question 5

In DNA sequencing, the difference between a forward and reverse primer is:

Accepted Answer

Forward primers bind to the 5' end, while reverse primers bind to the 3' end of the template strand.

Answer

Forward primers bind to the 3' end, while reverse primers bind to the 5' end of the template strand.

Answer

Forward primers are labeled with fluorescent dyes, while reverse primers are not.

Answer

Forward primers are used for PCR amplification, while reverse primers are used for sequencing.

Question 6

Which of the following is **not** a common application of DNA sequencing in medicine?

Accepted Answer

Predicting disease risk with certainty

Answer

Forensic identification

Answer

Diagnosis of genetic diseases

Answer

Tailoring medical treatments

Question 7

Which DNA sequencing method is primarily used for sequencing short fragments (up to approximately 1000 base pairs)?

Accepted Answer

Sanger sequencing

Answer

Next-generation sequencing (NGS)

Question 8

The Sanger sequencing method relies on which principle?

Accepted Answer

Chain termination

Answer

Pyrosequencing

Question 9

Which is NOT an advantage of next-generation sequencing (NGS) over Sanger sequencing?

Accepted Answer

Increased accuracy

Answer

Lower cost per base

Question 10

Preparing DNA samples for sequencing typically involves which step?

Accepted Answer

Fragmentation and ligation

Answer

PCR amplification

Question 11

Which bioinformatics tool is commonly used for aligning sequencing reads to a reference genome?

Accepted Answer

BWA

Answer

FASTA

Question 12

What is the purpose of using dideoxynucleotides (ddNTPs) in Sanger sequencing?

Accepted Answer

To terminate the extension of the primer strand

Answer

To increase the fidelity of DNA polymerase

Answer

To prevent the formation of secondary structures in the DNA template

Answer

To label the DNA fragments with fluorescent markers

Question 13

Which of the following is a key difference between Sanger sequencing and next-generation sequencing (NGS)?

Accepted Answer

The number of DNA fragments that can be sequenced simultaneously

Answer

The length of the DNA fragments that can be sequenced

Answer

The accuracy of the sequencing results

Answer

The cost of the sequencing procedure

Question 14

What is the role of a sequencing primer in DNA sequencing?

Accepted Answer

To bind to a specific region of the DNA template and initiate DNA synthesis

Answer

To terminate the extension of the primer strand

Answer

To label the DNA fragments with fluorescent markers

Answer

To separate the DNA fragments by electrophoresis

Question 15

What is the purpose of using capillary electrophoresis in DNA sequencing?

Accepted Answer

To separate DNA fragments based on their size

Answer

To amplify the DNA fragments

Answer

To label the DNA fragments with fluorescent markers

Answer

To determine the sequence of the DNA fragments

Question 16

What is the advantage of using paired-end sequencing in NGS?

Accepted Answer

It provides longer reads, which improves the accuracy of the assembly

Answer

It reduces the number of sequencing errors

Answer

It decreases the cost of sequencing

Answer

It allows for the detection of structural variants

Question 17

Which of the following best describes the fundamental principle of Sanger sequencing?

Accepted Answer

Gel electrophoresis of amplified fragments with fluorescently labeled primers

Answer

Electrophoresis of fragments generated by restriction enzyme digestion

Answer

Separation of fragments by size in capillary electrophoresis

Answer

Hybridization of a labeled probe to a complementary sequence

Question 18

Which of the following is NOT considered an advantage of next-generation sequencing (NGS) over Sanger sequencing?

Accepted Answer

Shorter read lengths

Answer

Increased throughput and efficiency

Answer

Lower cost per base sequenced

Answer

Capacity for whole-genome sequencing

Question 19

Which key step in NGS library preparation involves breaking down DNA into smaller fragments?

Accepted Answer

DNA fragmentation

Answer

Library preparation

Answer

Amplification

Answer

Hybridization

Question 20

In NGS, what is the primary function of the sequencing adapter?

Accepted Answer

Attachment of fragments to the flow cell

Answer

Binding site for the sequencing primer

Answer

Enabling directional sequencing

Answer

Enhancing signal-to-noise ratio

Question 21

What is the primary role of bioinformatics in the analysis of DNA sequencing data?

Accepted Answer

Encompasses all of the above

Answer

Assembling sequence reads

Answer

Identifying genetic variations

Answer

Annotating genomic features

Question 22

What are some anticipated future directions for DNA sequencing technology development?

Accepted Answer

Encompasses all of the above

Answer

Development of affordable, portable sequencing devices

Answer

Advancements in sequencing precision and accuracy

Answer

Miniaturization of sequencing platforms