STP Genomics & Molecular Biology

Question 1

Which enzyme is primarily responsible for synthesizing new DNA strands during replication in eukaryotes?

Accepted Answer

DNA Polymerase δ

Answer

DNA Polymerase α

Answer

RNA Polymerase II

Answer

Reverse transcriptase

Question 2

What is the primary purpose of the polymerase chain reaction (PCR) in a clinical laboratory setting?

Accepted Answer

To amplify a specific DNA or RNA target for detection or analysis

Answer

To sequence an entire genome

Answer

To measure gene expression levels directly

Answer

To determine protein structure from nucleotide sequence

Question 3

A single nucleotide polymorphism (SNP) is best described as:

Accepted Answer

A variation in a single base pair at a specific locus occurring in ≥1% of the population

Answer

A large chromosomal deletion affecting multiple genes

Answer

An insertion of a transposable element into a coding region

Answer

A change in the number of chromosomal copies

Question 4

In gel electrophoresis of DNA, smaller fragments migrate:

Accepted Answer

Faster and further from the wells than larger fragments

Answer

Towards the negative electrode (cathode)

Answer

More slowly than larger fragments

Answer

At the same rate regardless of size if voltage is constant

Question 5

Which molecular technique uses sequence-specific probes to detect target DNA within intact chromosomal preparations?

Accepted Answer

Fluorescence in situ hybridisation (FISH)

Answer

Southern blotting

Answer

Comparative genomic hybridisation (CGH)

Answer

Quantitative PCR (qPCR)

Question 6

Restriction endonucleases are most commonly used in molecular biology to:

Accepted Answer

Cleave double-stranded DNA at specific recognition sequences

Answer

Remove RNA primers during DNA replication

Answer

Join DNA fragments together in cloning procedures

Answer

Synthesise complementary DNA from an RNA template

Question 7

Next-generation sequencing (NGS) differs from Sanger sequencing primarily in that it:

Accepted Answer

Can sequence millions of DNA fragments simultaneously in a massively parallel manner

Answer

Uses dideoxynucleotide chain terminators to determine base sequence

Answer

Requires substantially more template DNA than first-generation methods

Answer

Produces longer individual reads than any first-generation method