Chromosome

DNA is a molecule that carries the cell's genetic information, encoding all proteins essential for cell structure and function. Proteins, through their specific structures and activities, determine the cell’s shape (e.g., cytoskeletal proteins) and facilitate vital cellular processes, such as sugar metabolism. To function properly, proteins must be synthesized precisely according to the patterns encoded in DNA. It is therefore essential for the DNA to remain intact throughout the cell's life. Any disruption in DNA can have significant consequences, such as cancer or other severe diseases. Given its fragility, DNA requires careful handling within the cell. In eukaryotic cells, this is achieved by wrapping DNA around proteins known as histones. Histones group into sets of four, around which DNA loops to form units called nucleosomes. These nucleosomes then link together, forming a compact spiral structure called chromatin, the material that composes chromosomes. Chromosomes are stored in the cell nucleus, and their number varies across species; humans have 46 chromosomes in a diploid state, fruit flies have 8, and dogs have 78.