Which structures are involved in compacting DNA into higher-order structures?

Which structures are involved in compacting DNA into higher-order structures?

• A. Histones
• B. Lipids
• C. Carbohydrates
• D. Nucleotides

Answer: (A)

DNA packaging into higher-order chromatin structures is driven by histone proteins. DNA wraps around a histone octamer to form a nucleosome, the bead-like unit of chromatin. The histones’ positive charges interact with the negatively charged DNA backbone, allowing tight wrapping and neutralizing charge to enable folding. Adding linker histone H1 promotes further condensation, helping nucleosomes coil into more compact fibers and eventually into looped domains that fit into the nucleus. The other options aren’t directly involved in organizing DNA: lipids form membranes, carbohydrates have other structural or energy roles, and nucleotides are the building blocks of DNA rather than the packaging proteins.

DNA packaging into higher-order chromatin structures is driven by histone proteins. DNA wraps around a histone octamer to form a nucleosome, the bead-like unit of chromatin. The histones’ positive charges interact with the negatively charged DNA backbone, allowing tight wrapping and neutralizing charge to enable folding. Adding linker histone H1 promotes further condensation, helping nucleosomes coil into more compact fibers and eventually into looped domains that fit into the nucleus. The other options aren’t directly involved in organizing DNA: lipids form membranes, carbohydrates have other structural or energy roles, and nucleotides are the building blocks of DNA rather than the packaging proteins.