Final answer:
The correct answer is that DNA wraps around histones to form nucleosomes in the nucleus. Histones are proteins that organize DNA into a compact structure, enabling efficient packaging inside the nucleus. Thus, option b) histones; nucleosomes is the correct choice.
Step-by-step explanation:
In the nucleus, RNA is not the molecule that is primarily involved in forming a compact structure around proteins. Instead, it is DNA that wraps around proteins to create the necessary structure within the nucleus. The correct statement is that DNA is wrapped around proteins known as histones to form structures called nucleosomes. These nucleosomes are further compacted into fibers that contribute to the overall structure of chromatin within the nucleus.
For eukaryotic cells, the arrangement of DNA into a condensed and organized structure is crucial because it allows a vast amount of genetic material to be efficiently packaged inside the small space of the nucleus. Histones play a key role in this process, as these are evolutionarily conserved proteins that associate with DNA to form the nucleosome, sometimes described visually as "beads on a string."
Therefore, the correct answer to the question 'In the nucleus, RNA is wrapped around _____ to form _____.' is b) histones; nucleosomes.