Chromosome Structure
Ever wondered what's packed inside your cells? Your DNA is organized into chromosomes, rod-shaped structures made of DNA wrapped around proteins. Think of it like a long string (DNA) wrapped tightly around spools (proteins called histones).
Before a cell divides, it must copy all its DNA. This DNA-protein complex in its loose form is called chromatin. When a cell prepares to divide, the chromatin coils up tightly to form visible chromosomes.
After copying, each chromosome has two identical halves called sister chromatids. These sister chromatids are connected at a pinched region called the centromere, making the chromosome look like an X.
Did You Know? If you stretched out all the DNA from a single human cell, it would be about 6 feet long! Histones help package this enormous amount of DNA into a space small enough to fit inside a microscopic cell.
