Which statement is true? multiple choice
a. only the lagging strand requires the enzyme primase.
b. once helicase has initially opened up the dna double helix, it dissociates from the dna allowing single-strand binding proteins and dna polymerase to bind.
c. primase is capable of synthesizing rna without attaching the incoming nucleotide to a pre-existing, free, 3' hydroxyl group.
d. dna polymerase is capable of synthesizing dna without attaching the incoming nucleotide to a pre-existing, free, 3' hydroxyl group.
e. dna polymerase incorporates new nucleotides into the growing dna molecule by forming hydrogen bonds between complementary nucleotides on the template.

c. Primase is capable of synthesizing RNA without attaching the incoming nucleotide to a pre-existing, free, 3' hydroxyl group.

Explanation:

Primase is a RNA Polymerase involved in the process of DNA replication. DNA Polymerase is not able to initiate DNA replication without a primer because it needs a free 3'-OH (hydroxyl) group to add nucleotides. Primase does not require a free 3'OH group and makes a short RNA primer complementary to template DNA strand. DNA Polymerase can add nucleotides to this primer and initiate the process of replication. Later the RNA primer is replaced by DNA via 5' to 3' exonuclease.

To initiate DNA replication primase binds to DNA helicase forming a complex called as primosome. It then synthesizes a primer approximately 11 nucleotides long which can be extended by DNA Polymerase.