Question

During transcription in eukaryotes, a type of RNA polymerase called RNA polymerase II moves along the template strand of the DNA in the 3'→5' direction. However, for any given gene, either strand of the double-stranded DNA may function as the template strand. Which of the following initially determines which DNA strand is the template strand, and therefore in which direction RNA polymerase II moves along the DNA?

A. the location of specific proteins (transcription factors) that bind to the DNA
B. the specific sequence of bases along the DNA strands
C. the location along the chromosome where the double-stranded DNA unwinds
D. the position of the gene’s promoter on the chromosome
E. which of the two strands of DNA carries the RNA primer

Answer 1

Answer:

D. the position of the gene’s promoter on the chromosome

Explanation:

Transcription is the first stage of gene expression or protein synthesis. It is the process of synthesizing a complementary strand of mRNA from a DNA template. This synthesis of complementary RNA strand I carried out by an enzyme called RNA polymerase. RNA polymerase does this by adding complementary nucleotides to the growing RNA strand (3'-5') based on the nucleotide it reads on the 5'-3' of the DNA template.

Before transcription can start, the RNA polymerase needs to recognize and bind to a specific region of the gene called PROMOTER. This signals initiation of the transcription process and also tells the polymerase which unwinded strand of DNA will serve as the template strand and hence, in what direction nucleotides will be added.

N.B: Only one of the separated DNA strands will serve as a template for the synthesis of RNA