Question

A = adenine T = thymine C = cytosine G = guanine U = uracil A DNA strand is used as a template to make an RNA strand. Write out the complementary RNA bases for the following DNA sequence: A C G G T T

Answer 1

When a DNA strand is used as a template to make an RNA strand, the first step in gene expression is followed which is known as Transcription. The process of Transcription is carried out by an enzyme called RNA polymerase. The primary function of an RNA polymerase is to link nucleotides to form an RNA strand using DNA strand as a template in 5' to 3' direction linking each new nucleotide to the 3' end of the strand.

The thumb rule of complementary base pairing is as follows:

• Cytosine (C) is replaced with Guanine (G)
• Guanine (G) is replaced with Cytosine (C)
• Adenine (A) is replaced by Thymine (T)
• Thymine (T) is replaced by Adenine (A)
• Uracil (U) is replaced by Adenine (A) [The RNA transcript carries the same information as the coding strand of DNA, but it contains the base Uracil (U) instead of Thymine (T)]

Hence, the complementary RNA bases for the given DNA squences will be as follows:

1) A C G

U G C

2) G T T

C A A