Which enzyme initiates the synthesis of DNA by creating a short RNA segment during DNA replication?

• A. DNA polymerase
• B. Primase
• C. Ligase
• D. Helicase

Answer: (B)

Verified step by step guidance

1. Understand the process of DNA replication: DNA replication is the process by which a DNA molecule is copied to produce two identical DNA molecules. It involves several enzymes, each with a specific role.
2. Identify the role of the enzyme in question: The enzyme that initiates DNA synthesis does so by creating a short RNA primer. This primer provides a starting point for DNA polymerase to begin adding DNA nucleotides.
3. Recall the function of Primase: Primase is the enzyme responsible for synthesizing the short RNA primer during DNA replication. This primer is complementary to the DNA template strand.
4. Differentiate the roles of other enzymes: DNA polymerase extends the DNA strand by adding nucleotides, helicase unwinds the DNA double helix, and ligase joins Okazaki fragments on the lagging strand. None of these enzymes create the RNA primer.
5. Conclude that Primase is the correct enzyme: Based on its specific function of creating the RNA primer, Primase is the enzyme that initiates the synthesis of DNA during replication.