What is the structure of a chromosome primarily described as?

The structure of a chromosome is primarily described as a complex of DNA and protein. Chromosomes are made up of tightly coiled DNA wrapped around histone proteins, which help package the DNA into a compact, organized structure. This intricate arrangement is essential for the proper segregation of genetic material during cell division. While the DNA within each chromosome does exhibit a double helix formation at the molecular level, it is the combination of DNA and proteins that defines the structural characteristics of chromosomes as they exist in cells, particularly during the phases of mitosis and meiosis. This complex structure also plays a critical role in regulating gene expression and ensuring the stability of the genetic material.