Final answer:
DNA is organized into locally folded domains that are evidenced by chromosome conformation capture due to the compact structure of DNA wrapping around nucleosomes, forming a 'beads on a string' structure and further condensation into chromatin fibers.
Step-by-step explanation:
Chromosome conformation capture techniques suggest that DNA is organized into locally folded domains due to the compact structure of DNA when wrapped around nucleosomes, and the further higher-order folding into the chromatin structure. In eukaryotic cells, DNA is tightly wrapped around histones to form nucleosomes, resembling 'beads on a string'. This structure is further compacted into a 30 nm fiber which forms loops, rosettes, and coils, ultimately forming the condensed chromosome seen during metaphase. These multiple levels of compaction are essential for fitting the long DNA molecules into the microscopic nuclear space.
The nucleosomes consist of an octamer of histone proteins with DNA wrapped around them, linked together by linker DNA. Between higher levels of compaction, euchromatin is less condensed and contains actively transcribed genes, whereas heterochromatin is more condensed and typically contains inactive genes.
During mitosis, the chromatin further condenses, allowing the chromosomes to be distributed to daughter cells efficiently. Through these stages of compaction, the 2-meter long human cell DNA is intricately folded to fit into a cell nucleus that is only about 5-10 micrometer in diameter.