FDC DNA Analysis Techniques 5

Question 1

What is the primary function of proteinase K in the DNA extraction process?

Accepted Answer

To digest proteins and inactivate nucleases that would degrade DNA

Answer

Proteinase K digests cellular proteins, including nucleases (DNases) that would otherwise degrade the DNA, helping to release and protect the extracted DNA.

Question 2

In forensic toxicogenomics, what type of variation is most commonly studied to predict drug metabolism phenotypes?

Accepted Answer

Single nucleotide polymorphisms (SNPs) in cytochrome P450 genes

Answer

SNPs in cytochrome P450 genes (e.g., CYP2D6, CYP2C19) are the most commonly studied variants for predicting whether individuals are poor, intermediate, or ultra-rapid drug metabolizers.

Question 3

What is 'touch DNA,' and what challenge does it pose for forensic analysis?

Accepted Answer

Low-quantity DNA shed from skin cells through contact; challenge is stochastic effects and contamination

Answer

Touch DNA refers to the trace amounts of cellular material shed through skin contact; its low quantity makes it susceptible to stochastic effects (allelic dropout, imbalance) and contamination.

Question 4

Which quality assurance document establishes guidelines for forensic DNA testing laboratories in the US?

Accepted Answer

SWGDAM Guidelines and FBI QAS standards

Answer

The FBI's Quality Assurance Standards (QAS) and SWGDAM guidelines set the requirements for accreditation and quality practices for forensic DNA laboratories in the US.

Question 5

What is the purpose of the denaturation step in PCR thermal cycling?

Accepted Answer

To separate double-stranded DNA into single-stranded templates

Answer

Denaturation (typically ~95°C) breaks the hydrogen bonds between complementary base pairs, separating the double-stranded DNA into single-stranded templates for primer annealing.

(FDC) Forensic DNA Certification Practice Test

(FDC) Forensic DNA Certification Practice Test

FDC DNA Analysis Techniques 5