Which of the following enzymes is responsible for RNA synthesis during transcription?

• A. Helicase
• B. RNA polymerase
• C. DNA ligase
• D. Topoisomerase

Answer: (B)

Verified step by step guidance

1. Understand the process of transcription: Transcription is the process by which the genetic information in DNA is copied into RNA. This is the first step in gene expression.
2. Identify the role of enzymes in transcription: Enzymes are biological catalysts that speed up chemical reactions. In transcription, specific enzymes are responsible for synthesizing RNA from a DNA template.
3. Recognize the function of RNA polymerase: RNA polymerase is the enzyme that catalyzes the synthesis of RNA by adding ribonucleotides in a sequence complementary to the DNA template strand.
4. Differentiate between the given enzymes: Helicase unwinds the DNA double helix, DNA ligase joins DNA fragments, and Topoisomerase relieves the tension in the DNA helix. None of these are directly involved in RNA synthesis during transcription.
5. Conclude that RNA polymerase is the enzyme responsible for RNA synthesis during transcription, as it directly facilitates the formation of RNA strands from the DNA template.