Question

RNA polymerase binds to a specific nucleotide sequence near the start of transcription known as a/an:

A) Operator
B) Promoter
C) Enhancer
D) Silencer

Answer 1

RNA polymerase binds to the promoter, a specific DNA sequence upstream of a gene, to initiate transcription. This promoter region includes the TATA box, which plays a key role in the process.

Step-by-step explanation:

RNA polymerase binds to a specific nucleotide sequence near the start of transcription known as a promoter. This DNA sequence is crucial for the initiation of transcription as it determines the exact location where RNA polymerase should bind and start synthesizing RNA. The promoter exists upstream of the gene it regulates and includes specific regions such as the TATA box (a sequence of thymine and adenine dinucleotides), which is recognized by various transcription factors. In eukaryotic cells, the TATA box within the promoter is crucial for positioning the RNA polymerase and associated transcription factors to initiate transcription. Once RNA polymerase is bound to the promoter, the DNA double helix is unwound, forming a transcription bubble, allowing the RNA synthesis to begin.