Question

Transcription begins when RNA polymerase binds to the ____.

a.) initiator on DNA.
b.) promoter on DNA.
c.) terminator on DNA.
d.) promoter on RNA.

Answer 1

RNA polymerase initiates transcription by binding to the d) promoter on DNA, which directs the synthesis of mRNA starting from the correct site.

Step-by-step explanation:

Transcription begins when RNA polymerase binds to the promoter on DNA. This event marks the initiation of transcription and is essential for the synthesis of mRNA. The promoter is a specific DNA sequence that orients the RNA polymerase to start transcription at the correct site. Once bound to the promoter, RNA polymerase unwinds the DNA, forming a transcription bubble, and starts synthesizing RNA by reading the template strand of DNA.

During this process, a complex known as the initiation complex is formed, and as transcription progresses, nucleotides are added to the mRNA strand in a phase known as elongation. When RNA polymerase transcribes a terminator sequence, it detaches from the DNA, and the newly formed mRNA strand is released, completing the transcription process.