Heterochromatin differs from euchromatin in that heterochromatin
a. contains dna with accessible promoters.
b. is transcriptionally active, whereas euchromatin is not.
c. is the result of the unpacking of euchromatin.
d. is transcriptionally inactive.

D. is transcriptionally inactive.

Explanation:

Euchromatin is the part of chromosomes which are loose in form and are involved in the transcription process because these are available for the transcription into specific protein products. On the other hand, heterochromatin is the region of chromosomes that appears dark in staining process. This region is transcriptionally inactive because of the DNA template in the DNA-protein complexes and which means that genes present in the region are not active and not involved in the process of transcription.

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