Question

Shown is a stretch of DNA containing a promoter and a very small open reading frame (ORF).  What is the base of the first nucleotide in the RNA transcript that would be produced from this gene?

Group of answer choices

C

U

A

G

T

Answer 1

ANSWER ) A

EXPLAINATION

AUG WILL BE START CODON FROM THE RNA TRANSCRIPT OF THE GENE FROM WHICH METHIONINE WILL BE FIRST INCORPORATED

The start codon in a coding sequence of DNA is almost always the sequence ATG (transcribed as AUG in mRNA). It has two functions:

(1) telling the ribosome where to begin reading the RNA and assembling the translated protein sequence*, and

(2) coding for the amino acid methionine , which is why most newly translated proteins start with methionine.