Question

a stretch of which nucleotide in the DNA acts as the terminationsignal​

Answer 1

The stretch of Uracil(form of nucletlotide acts as termination signal)

Answer 2

RNA POLYMERASE

The stretch of nucleotide namely POLY A acts as the termination signal.

EXPLANATION:

*The termination sequence consists of a hairpin loop followed by a length of oligo U nucleotides.

*This next length of the "U" residue pairs poorly with the DNA's "A" residues, allowing for facile separation.

*Destabilization of the elongation complex, followed by release of the elongation complex, nascent RNA, and polymerase, is required for transcription termination.