Final answer:
Active genes in eukaryotic cells are associated with euchromatin, which is less densely packed than heterochromatin, allowing for increased accessibility to transcription factors due to histone acetylation.
Step-by-step explanation:
The active genes associated with loosely packed chromatin in eukaryotic transcription are typically found in euchromatin. This form of chromatin is characterized by a less condensed structure and is hence more accessible for the transcription machinery.
Experiments involving treatment with deoxyribonuclease (DNAse) have shown that DNA in active genes is more susceptible to degradation, implying that these genes are in euchromatin, which has less coiled DNA and fewer surrounding proteins as compared to heterochromatin.
Furthermore, histone acetylation is known to result in the loosening of nucleosome packing, thereby facilitating the binding of transcription factors and gene expression. This modification is one way that chromatin structure is dynamically altered to regulate gene expression.