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5.3 Chromatin & Epigenetic Regulation — Test 1
Q1. Genomic imprinting is:✓ Parent-of-origin-dependent expression of genes
Q2. Eastern blotting detects:✓ Post-translational modifications of proteins
Q3. miRNA-based gene silencing is a type of:✓ Post-transcriptional gene silencing
Q4. Virus-induced gene silencing (VIGS) exploits which natural defence?✓ RNAi-mediated antiviral defence
Q5. Which modification is NOT directly an epigenetic (chromatin/DNA) mark?✓ Protein N-glycosylation
Q6. Epigenetic factor binding across the genome is commonly mapped by:✓ ChIP (chromatin immunoprecipitation)-based methods
Q7. Heterochromatin is generally:✓ Densely packed and transcriptionally silent
Q8. Histone acetylation (by HATs) generally:✓ Loosens chromatin and promotes transcription
Q9. X-chromosome inactivation in female mammals is initiated by:✓ The long non-coding RNA Xist coating one X
Q10. ATP-dependent chromatin remodeling complexes (e.g. SWI/SNF) function to:✓ Slide or evict nucleosomes to change DNA accessibility
Q11. DNA methylation in mammals occurs mainly at:✓ Cytosines in CpG dinucleotides
Q12. Which histone mark is associated with ACTIVE promoters?✓ H3K4me3
Q13. Polycomb (PRC2) complexes repress genes by depositing:✓ H3K27me3
Q14. Position-effect variegation reflects:✓ Spreading of heterochromatin silencing a nearby gene in some cells
Q15. CpG-island promoter methylation typically leads to:✓ Stable transcriptional silencing
Q16. The 'histone code' hypothesis proposes that:✓ Combinations of histone modifications are read by proteins to set chromatin states
Q17. Facultative heterochromatin differs from constitutive heterochromatin in that it:✓ Can switch between active and silent states depending on cell type/stage
Q18. TET enzymes contribute to epigenetic regulation by:✓ Oxidising 5-methylcytosine toward demethylation (gene de-repression)
Q19. Genomic imprinting control regions are established by:✓ Parent-specific (germline) DNA methylation marks
Q20. Which best describes euchromatin?✓ Open, accessible and generally transcriptionally active