How does heterochromatin differ from euchromatin?

Heterochromatin is indeed characterized by its staining properties, specifically staining darkly during chromosome banding. This darker staining is indicative of the tightly packed nature of heterochromatin, which contains fewer genes and is generally transcriptionally inactive. The compact structure of heterochromatin makes it less accessible to the transcriptional machinery, which is why it is not involved in active gene expression.

In contrast, euchromatin is less densely packed, allowing for a more accessible structure that facilitates active transcription. It typically appears lighter during chromosome banding due to this looser configuration, which is conducive to the processes of transcription and replication. This difference in structure and staining reflects the divergent roles of these chromatin types in cellular function.

The other options suggest properties or behaviors that do not correctly describe the distinctions between heterochromatin and euchromatin. For instance, heterochromatin is primarily found in a transcriptionally inactive state, while euchromatin is known for being transcriptionally active. Methylation status varies, but euchromatin is not universally heavily methylated. Additionally, during replication, both heterochromatin and euchromatin undergo changes, but only euchromatin is typically described as less condensed compared to the way heter