During DNA replication, what is the primary function of the enzyme helicase?

• A. It joins Okazaki fragments together on the lagging strand.
• B. It unwinds the double-stranded DNA by breaking hydrogen bonds between the bases.
• C. It removes RNA primers from the newly synthesized DNA.
• D. It synthesizes new DNA strands by adding nucleotides to a primer.

Answer: (B)

Verified step by step guidance

1. Understand the process of DNA replication: DNA replication is the biological mechanism by which a cell duplicates its DNA before cell division. It involves several enzymes, each with a specific role.
2. Identify the role of helicase: Helicase is an enzyme responsible for unwinding the double-stranded DNA. It does this by breaking the hydrogen bonds between complementary base pairs (adenine-thymine and guanine-cytosine).
3. Clarify why unwinding is necessary: The unwinding of DNA by helicase creates a replication fork, exposing the single-stranded DNA templates needed for the synthesis of new DNA strands.
4. Differentiate helicase from other enzymes: Helicase does not synthesize DNA, join Okazaki fragments, or remove RNA primers. These tasks are performed by other enzymes such as DNA polymerase, ligase, and exonuclease, respectively.
5. Summarize the function of helicase: Helicase's primary function is to initiate DNA replication by unwinding the double-stranded DNA, enabling other enzymes to access the single-stranded templates for replication.