STP Genomics & Molecular Biology 2

Question 1

A genome-wide association study (GWAS) is designed primarily to:

Accepted Answer

Identify statistical associations between common genetic variants and specific traits or diseases

Answer

Sequence every coding exon in an individual's genome

Answer

Detect de novo mutations arising in a single generation

Answer

Determine the three-dimensional structure of the genome

Question 2

Copy number variations (CNVs) refer to:

Accepted Answer

Segments of DNA ≥1 kb present in a variable number of copies relative to a reference genome

Answer

Point mutations that alter a single amino acid in a protein

Answer

Epigenetic modifications that alter gene expression without changing the DNA sequence

Answer

Chromosomal translocations between non-homologous chromosomes

Question 3

RNA sequencing (RNA-seq) is used in clinical and research genomics to:

Accepted Answer

Quantify and characterise the transcriptome, including expression levels and splicing variants

Answer

Amplify specific RNA targets using reverse-transcribed cDNA only

Answer

Edit specific RNA sequences using base-editing enzymes

Answer

Detect chromosomal aneuploidies from cell-free RNA in plasma

Question 4

CRISPR-Cas9 gene editing works by:

Accepted Answer

Guided RNA directing the Cas9 endonuclease to a specific genomic sequence where it introduces a double-strand break

Answer

Using restriction enzymes to make blunt-end cuts at random genomic locations

Answer

Inserting foreign DNA via retroviral integration at semi-random sites

Answer

Methylating specific promoter regions to silence targeted genes

Question 5

In genomic medicine, a 'variant of uncertain significance' (VUS) means that:

Accepted Answer

Insufficient evidence exists to classify the variant as pathogenic or benign

Answer

The variant is confirmed to cause the patient's disease

Answer

The variant is benign and can be dismissed from clinical consideration

Answer

The variant has been found only in population databases, never in patients

Question 6

Pharmacogenomics is primarily concerned with:

Accepted Answer

How genetic variation influences an individual's response to drugs, including efficacy and adverse reactions

Answer

Developing new drugs using recombinant DNA technology

Answer

Measuring drug concentrations in plasma using mass spectrometry

Answer

Screening drug candidates for mutagenic potential

Question 7

Whole exome sequencing (WES) targets approximately what proportion of the human genome?

Accepted Answer

~1–2% of the genome, encompassing protein-coding exons

Answer

~50% of the genome, including all repetitive elements

Answer

~10% of the genome, including all regulatory regions

Answer

~0.01% of the genome, covering only known pathogenic variants