What is the main characteristic of euchromatin?

The main characteristic of euchromatin is that it consists of loosely packed DNA. This less condensed structure allows for greater accessibility of the DNA to transcription machinery, facilitating active gene expression. Euchromatin is typically associated with actively transcribed genes, as its structure permits the necessary proteins to bind to the DNA and initiate transcription.

The loosely packed nature of euchromatin contrasts with heterochromatin, which is tightly packed and generally associated with gene repression. The accessibility provided by euchromatin makes it essential for processes such as transcription and DNA replication, enabling cells to efficiently express the genes they need at any given time.