Chromosomes and chromatin Original Scenario-Based Download PDF

Questions

1. 1.

   During an exploratory simulation inside the nucleus of an engineered synthetic organism, nanobot probe Astra-1 navigates along an intricate macromolecular fiber. Sensors detect double-stranded nucleic acid wrapping precisely around globular protein spools before folding into distinct domains of variable accessibility. Which statement accurately describes the structural organization of chromatin and chromosomes reflected in this architecture?

   • A) Histones carry a strong negative charge that naturally repels the phosphate backbone of DNA, requiring continuous ATP-dependent clamps to maintain spooling.
   • B) Throughout interphase, genomic DNA remains uniformly packed into maximally condensed metaphase chromosomes to shield coding sequences from chemical damage.
   • C) The fundamental repeating unit is the nucleosome, in which negatively charged DNA wraps around an octamer of positively charged histone proteins.
   • D) Heterochromatin constitutes the loosely packed, open chromatin conformation that actively promotes high rates of continuous transcription.