To achieve condensation, DNA wraps around a group of ________ molecules, forming a nucleosome.

To achieve condensation, DNA wraps around a group of ________ molecules, forming a nucleosome.

• A. Histone
• B. Enzyme
• C. Carbohydrate
• D. Lipid

Answer: (A)

DNA condensation is achieved when DNA winds around histone proteins to form nucleosomes. Histones are small, highly basic proteins with positive charges that bind the negatively charged DNA backbone, allowing about 146 base pairs of DNA to wrap around a histone octamer. This bead-like unit, with linker DNA and sometimes the linker histone H1, stacks into higher-order fibers to compact the genome inside the nucleus. Enzymes, carbohydrates, and lipids don’t provide the structural core needed for this wrapping, so they don’t form nucleosomes.

DNA condensation is achieved when DNA winds around histone proteins to form nucleosomes. Histones are small, highly basic proteins with positive charges that bind the negatively charged DNA backbone, allowing about 146 base pairs of DNA to wrap around a histone octamer. This bead-like unit, with linker DNA and sometimes the linker histone H1, stacks into higher-order fibers to compact the genome inside the nucleus. Enzymes, carbohydrates, and lipids don’t provide the structural core needed for this wrapping, so they don’t form nucleosomes.