Which enzyme is responsible for adding new nucleotides to the end of a growing $\mathrm{DNA}$ strand during replication?

• A. $\mathrm{RNA}$ polymerase
• B. $\mathrm{DNA}$ polymerase
• 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 cell duplicates its DNA, resulting in two identical copies. This process is crucial for cell division.
2. Identify the role of enzymes in DNA replication: Several enzymes are involved in DNA replication, each with a specific function. Key enzymes include DNA polymerase, helicase, ligase, and primase.
3. Focus on DNA polymerase: DNA polymerase is the enzyme responsible for synthesizing new DNA strands by adding nucleotides to the growing strand. It reads the template strand and adds complementary nucleotides to form the new strand.
4. Differentiate between DNA polymerase and other enzymes: RNA polymerase is involved in transcription, not replication. Helicase unwinds the DNA double helix, and ligase joins Okazaki fragments on the lagging strand.
5. Conclude with the correct enzyme: Based on the roles of these enzymes, DNA polymerase is the enzyme that adds new nucleotides to the end of a growing DNA strand during replication.