Question

During transcription does dna double helix opens up

Answer 1

It moves forward along the template strand in the 3' to 5' direction, opening the DNA double helix as it goes. The synthesized RNA only remains bound to the template strand for a short while, then exits the polymerase as a dangling string, allowing the DNA to close back up and form a double helix.

Answer 2

Your answer is here.

Yes
In the transcription process a messenger RNA is made using one strand of the DNA double helix as the template. ... A mechanism of DNA replication has been proposed by the author.' In this mechanism, hydrogen-bonded base pairs are assumed to drift into the big groove of the DNA molecule side by side with the parent pairs.

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