FDC DNA Analysis Techniques 3

Question 1

What is the purpose of an internal size standard (ISS) in capillary electrophoresis?

Accepted Answer

To accurately size DNA fragments by providing reference peaks of known length

Answer

The internal size standard provides reference peaks of known fragment sizes, allowing the instrument software to accurately determine the size of unknown allele peaks.

Question 2

Which of the following best describes Y-STR analysis?

Accepted Answer

It analyzes paternal lineage using markers on the Y chromosome

Answer

Y-STR analysis examines short tandem repeats on the Y chromosome, which is paternally inherited, allowing investigators to trace male lineage.

Question 3

What is the significance of Hardy-Weinberg equilibrium in forensic DNA statistics?

Accepted Answer

It allows genotype frequencies to be calculated from allele frequencies assuming random mating

Answer

Hardy-Weinberg equilibrium allows forensic analysts to calculate expected genotype frequencies by multiplying allele frequencies, assuming a randomly mating population.

Question 4

Which step in DNA extraction is responsible for breaking open cell walls and membranes to release DNA?

Accepted Answer

Lysis

Answer

The lysis step uses detergents, enzymes (such as proteinase K), or physical methods to break open cells and release DNA from the cellular matrix.

Question 5

In forensic DNA analysis, what is a 'mixture interpretation threshold' (analytical threshold)?

Accepted Answer

The minimum peak height below which data is not used for interpretation

Answer

The analytical threshold is the minimum peak height (in RFU) below which data is considered noise and excluded from interpretation to prevent false allele calls.

(FDC) Forensic DNA Certification Practice Test

(FDC) Forensic DNA Certification Practice Test

FDC DNA Analysis Techniques 3