CSMLS Molecular Diagnostics 2

Question 1

What is the function of restriction endonucleases in molecular biology?

Accepted Answer

To cleave double-stranded DNA at specific palindromic recognition sequences

Answer

To amplify specific DNA sequences using thermal cycling

Answer

To join DNA fragments with complementary ends

Answer

To remove RNA primers from newly synthesized DNA

Question 2

16S rRNA gene sequencing is considered the gold standard for bacterial species identification because:

Accepted Answer

The gene contains conserved primer-binding regions flanking variable species-identifying regions

Answer

It amplifies only pathogenic bacteria

Answer

It detects antibiotic resistance genes directly

Answer

It can identify bacteria without prior culture

Question 3

In Southern blotting, why is the gel treated with alkali after electrophoresis?

Accepted Answer

To denature double-stranded DNA into single strands before transfer

Answer

To stain DNA bands for direct visualization

Answer

To neutralize the gel before probe hybridization

Answer

To digest non-target DNA before transfer to the membrane

Question 4

Which next-generation sequencing (NGS) platform uses fluorescently labeled reversible terminator nucleotides incorporated one base at a time?

Accepted Answer

Illumina sequencing by synthesis

Answer

Pacific Biosciences SMRT sequencing

Answer

Oxford Nanopore sequencing

Answer

Ion Torrent semiconductor sequencing

Question 5

Restriction fragment length polymorphism (RFLP) analysis detects genetic variation by:

Accepted Answer

Identifying sequence changes that create or abolish restriction enzyme recognition sites

Answer

Measuring differences in gene expression between individuals

Answer

Detecting chromosomal translocations with fluorescent probes

Answer

Quantifying copy number variants by real-time PCR

Question 6

Northern blotting is used to:

Accepted Answer

Detect and quantify specific mRNA transcripts in a sample

Answer

Detect specific DNA sequences in genomic samples

Answer

Identify specific proteins by antibody probing

Answer

Determine the chromosomal location of a gene

Question 7

Allele-specific PCR (AS-PCR) is designed primarily to:

Accepted Answer

Detect specific single nucleotide variants or point mutations

Answer

Amplify the entire coding sequence of a gene

Answer

Compare expression levels between two tissue types

Answer

Identify gene fusions in hematological malignancies