What is the function of a chromosome

The chromosome holds not only the genetic code, but many of the proteins responsible for helping express it. Its complex form and structure dictate how often genes can be translated into proteins, and which genes are translated. This process is known as gene expression and is responsible for creating organisms. Depending on how densely packed the chromosome is at certain point determines how often a gene gets expressed. As seen in the image of chromosome structure shown below, less active genes will be more tightly packed than genes undergoing active transcription. Cellular molecules that regulate genes and transcription often work by activing or deactivating these proteins, which can contract or expand the chromosome. During cell division, all the proteins are activated and the chromatin becomes densely packed into distinct chromosomes. These dense molecules have a better chance of withstanding the pulling forces that occur when chromosomes are separated into new cells.