- A Euchromatin is densely packed and transcriptionally active, while heterochromatin is loosely packed and transcriptionally inactive instead under typical conditions
- B Euchromatin is loosely packed, stains light, and is transcriptionally active; heterochromatin is densely packed, stains dark, and is transcriptionally inactive
- C Both forms of chromatin are equally condensed throughout, differing from one another mainly in their underlying base composition according to standard textbooks
- D Heterochromatin is understood to contain mainly RNA molecules within its structure, and no DNA whatsoever in general practice as commonly described in most textbook accounts
Correct answer: B. Euchromatin is loosely packed, stains light, and is transcriptionally active; heterochromatin is densely packed, stains dark, and is transcriptionally inactive
Explanation: Euchromatin is loosely packed chromatin that stains light and is generally transcriptionally active, while heterochromatin is tightly packed, stains dark, and is largely transcriptionally inactive.
Concept context
DNA structure, replication, transcription, translation, the genetic code, and gene regulation (lac operon). The single most important chapter for NEET molecular biology.