[Campbell Biology P.379] Which of the following statements accurately distinguishes euchroma... | Practice Question
Which of the following statements accurately distinguishes euchromatin from heterochromatin regarding their structure and function in gene expression?
A: Euchromatin is densely packed, and its genes are generally not expressed; heterochromatin is loosely arranged, and its genes are accessible for transcription.
B: Euchromatin is the basic unit of DNA packing, while heterochromatin is composed of multiple nucleosomes.
C: Euchromatin is loosely arranged and its DNA is accessible for proteins involved in transcription, allowing gene expression; heterochromatin is densely arranged and its genes are generally not expressed.
D: Euchromatin is found only in prokaryotic cells, whereas heterochromatin is exclusive to eukaryotic cells.
Explanation
Euchromatin is characterized by its looser arrangement, making its DNA accessible to transcription proteins and allowing gene expression. In contrast, heterochromatin is densely packed, rendering its genes generally inaccessible and therefore not expressed.