Question

At a specific area of a chromosome, the sequence of nucleotides below is present where the chain opens to form a replication fork: 3' C C T A G G C T G C A A T C C 5'. An RNA primer is formed starting at the underlined T (T) of the template.
A. 3 G C C T A G G 5
B. 5 G C C U A G G 3
C. 5 A C G U U A G G 3
D. 5 G C C T A G G 3
E. 5 A C G T T A G G 3

Answer 1

Answer: C. 5 A C G U U A G G 3

Explanation:

A primer is a short nucleic acid sequence that provides a starting point for DNA synthesis. It is a short strands of RNA.

DNA and RNA are made up of different sequence of nucleotides.

Adenine (A), Cytosine (C), and Guanine (G) are nucleotides found in both DNA and RNA.

Only DNA contains Thymine (T) and only RNA contains Uracil (U).

Pairing in DNA:

A to T

G to C

Pairing in RNA:

A to U

G to C.

Therefore DNA and RNA can still be complementary to one another by substituting for thymine (T) and Uracil (U) where required.

Starting from the underlined T (T) of the template, we have 3 T G C A A T C C 5.

If we are to pair the complementary RNA nucleotides, we will have 5 A C G U U A G G 3