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. Which of the following represents the primer sequence? A) 5' G C C T A G G 3' B) 3' G C C T A G G 5' C) 5' A C G T T A G G 3' D) 5' A C G U U A G G 3' E) 5' G C C U A G G 3

Answer 1

Answer:

The sequence of the primer for this open chain DNA replication fork is 5'ACGUUAGG3' Option D.

Explanation:

During the S phase of the mitotic division prior to cell multiplication, there is need to double the genetic make up of thr organism so as to maintain a conservation of the DNA. Replication start from the formation of primer at the replication fork of the genome, a primer is a short sequence RNA strand, which is needed to enable DNA polymerase to add DNA molecules using the parent strand. DNA replication including primer formation proceed by reading from the 3' to the 5' end, starting at a point where there is free hydroxyl group. This replication origin also start at the T and A rich region because it is easy to hydrolyse the double bounded molecules than the G and C rich.

Starting from the eight code with T, underlined, the complementary sequence that will be produced by the primase enzyme will be 5'ACGUUAGG3' which is option D, it should be noted that this sequence start from 5' and end in 3', and the sequence should not have T, since it's a RNA.