FDC DNA Analysis Techniques 2

Question 1

Which enzyme is used in PCR to synthesize new DNA strands during the extension step?

Accepted Answer

Taq polymerase

Answer

Taq polymerase, derived from Thermus aquaticus, is thermostable and synthesizes new DNA strands during the extension step of PCR.

Question 2

In capillary electrophoresis, what is the role of the polymer matrix inside the capillary?

Accepted Answer

To separate DNA fragments by size

Answer

The polymer matrix in capillary electrophoresis acts as a molecular sieve, separating DNA fragments by size as they migrate through under an electric field.

Question 3

What does the term 'stutter' refer to in STR analysis?

Accepted Answer

An artifact peak typically one repeat unit smaller than the true allele

Answer

Stutter is a PCR artifact that produces a minor peak typically one repeat unit smaller than the true allele, caused by slippage during replication.

Question 4

Which technique is used to determine the sequence of nucleotides in a mitochondrial DNA hypervariable region?

Accepted Answer

Sanger sequencing

Answer

Sanger sequencing (chain termination sequencing) is the standard method used to determine the nucleotide sequence of mitochondrial DNA hypervariable regions.

Question 5

What is the primary advantage of using fluorescently labeled primers in STR analysis?

Accepted Answer

They allow simultaneous detection of multiple loci in a single capillary run

Answer

Fluorescently labeled primers allow multiplexing, enabling simultaneous detection of multiple STR loci in a single capillary electrophoresis run using different dye colors.

(FDC) Forensic DNA Certification Practice Test

(FDC) Forensic DNA Certification Practice Test

FDC DNA Analysis Techniques 2