Chromatin structure refers to the organization of DNA and proteins within the nucleus of a cell. It consists of DNA wrapped around proteins called histones, forming a complex that helps package the long DNA strands into a compact form. This organization is crucial for DNA replication and gene expression, as it allows access to specific genes when needed. There are two main types of chromatin: euchromatin and heterochromatin. Euchromatin is loosely packed and generally associated with active gene transcription, while heterochromatin is tightly packed and often contains inactive genes. The dynamic nature of chromatin structure plays a key role in regulating cellular functions.