Which of the following is a restriction placed on DNA polymerase?
A) DNA polymerase can attach new nucleotides only in the 5' to 3' direction.
B) DNA polymerases must begin synthesis using an RNA primer.
C) DNA polymerases must have a template strand to copy from.
D) All of the above are restrictions of DNA polymerase.

Question

Quizplus · Accepted Answer

A) DNA polymerase can attach new nucleotides only in the 5' to 3' direction - This is due to the orientation of the sugar-phosphate backbone of DNA, which provides a specific binding site for the incoming nucleotide triphosphate that can only be added to the 3' end of the growing DNA chain.
B) DNA polymerases must begin synthesis using an RNA primer - This is necessary because DNA polymerases require a pre-existing 3' hydroxyl (-OH) group to begin adding new nucleotides. Since DNA itself does not provide this necessary starting point, a short RNA primer is used to prime the synthesis of new DNA strands during DNA replication.
C) DNA polymerases must have a template strand to copy from - In order to accurately replicate DNA, polymerases require a pre-existing template strand that serves as a guide to determine the correct sequence of nucleotides to add to the growing complementary strand. Without this template, DNA synthesis cannot occur.

Which of the Following Is a Restriction Placed on DNA