Answer:
a. positive; negative
Explanation:
Transcription is the process of forming an RNA molecule from a DNA template molecule. In this process, the strands of DNA separate and one serves as a template for RNA, while the other is inactive. At the end of the transcript, the tapes that have been split back together again.
The transcription process is divided into three steps: initiation, stretching and termination
During the stretching phase, transcription chain elongation occurs. In this phase the enzyme called RNA polymerase starts to move through the DNA molecule, unwinding its helix and producing an increasingly lengthened RNA molecule. The already transcribed DNA is rewound almost immediately, recomposing its double helix. This process is called the elongation phase.
During this process, it is believed that positive supercoils are generated ahead of the transcription bubble and and the negative supercoils behind it.
