Question

Those portions of DNA preceding the initiation site toward the 3' end of the template strand are said to be ______ that site.

a. upstream
b. downstream
c. to the right
d. to the left

Answer 1

The DNA regions prior to the initiation site towards the 3' end of the template strand are referred to as upstream.

Step-by-step explanation:

Those portions of DNA preceding the initiation site toward the 3' end of the template strand are said to be upstream of that site. The initiation of transcription begins at a promoter, which is typically located just upstream of the genes they regulate. The nucleotide pair in the DNA double helix that corresponds to the site from which the first 5' RNA nucleotide is transcribed is the initiation site. Nucleotides preceding this initiation site are considered upstream because they are located toward the 5' end of the encoding template strand, while nucleotides following the initiation site are described as downstream.