Master the PLTW Biomedical Science EOC 2026 – Unlock Your Inner Science Whiz!

DNA must be packaged into compact structures to fit inside the nucleus and to be reliably separated during cell division. In eukaryotic cells, DNA wraps around histone proteins to form nucleosomes, then folds into higher-order structures called chromatin, which condense further into visible chromosomes when a cell divides. So the structures DNA is packaged into are chromosomes. Other options describe different cellular components: ribosomes are the protein-synthesis machines; centromeres are specific regions on chromosomes where sister chromatids meet and spindle fibers attach; mitochondria are organelles that contain their own DNA but are not the packaged form of the genome.