AP BIOLOGY

Detailed explanation-1: -It involves copying a gene’s DNA sequence to make an RNA molecule. Transcription is performed by enzymes called RNA polymerases, which link nucleotides to form an RNA strand (using a DNA strand as a template). Transcription has three stages: initiation, elongation, and termination.

Detailed explanation-2: -The major steps of transcription are initiation, promoter clearance, elongation, and termination.

Detailed explanation-3: -DNA is double-stranded, but only one strand serves as a template for transcription at any given time. This template strand is called the noncoding strand. The nontemplate strand is referred to as the coding strand because its sequence will be the same as that of the new RNA molecule.

Detailed explanation-4: -The enzyme that converts DNA into mRNA is called RNA polymerase, which attaches to the DNA double helix as shown here. Once attached, RNA polymerase can unwind the helix and begin copying one of the DNA strands to form an mRNA transcript of the gene.