Final answer:
The next level of DNA organization after nucleosome formation is the coiling into a 30-nm chromatin fibre, which is followed by further compaction into chromosomes during cell division.
Step-by-step explanation:
After DNA loops around histone proteins to form nucleosome complexes, the next level of organization is the coiling of these nucleosomes along with the linker DNA into a 30-nm chromatin fibre. This process of coiling condenses the structure even further, creating a compact form of DNA that is significantly shorter than its extended version. The packing continues with additional levels, such as the arrangement of chromatin into loops and domains, and ultimately the supercoiling into chromosomes during cell division.