1. During DNA replication, what is the function of the enzyme helicase? A) To add new nucleotides to the growing DNA strand B) To seal the nicks in the sugar-phosphate backbone C) To unwind the DNA double helix D) To synthesize a primer for DNA polymerase Answer: C) To unwind the DNA double helix Rationale: Helicase is responsible for unwinding the DNA double helix, creating two single-stranded DNA templates for replication. 2. Which of the following best describes the role of DNA polymerase in DNA replication? A) It synthesizes RNA primers. B) It unwinds the DNA helix. C) It adds nucleotides to the 3' end of the growing DNA strand. D) It corrects mismatched base pairs. Answer: C) It adds nucleotides to the 3' end of the growing DNA strand. Rationale: DNA polymerase extends the DNA strand by adding nucleotides to the 3' end of the existing strand. 3. What is the significance of the leading and lagging strands during DNA replication? A) The leading strand is synthesized continuously, while the lagging strand is synthesized in fragments. B) The leading strand requires a primer, while the lagging strand does not. C) The leading strand is synthesized by DNA polymerase I, while the lagging strand is synthesized by DNA polymerase III. D) The leading strand is synthesized in the 5' to 3' direction, while the lagging strand is synthesized in the 3' to 5' direction. Answer: A) The leading strand is synthesized continuously, while the lagging strand is synthesized in fragments. Rationale: DNA replication is bidirectional and antiparallel; the leading strand is synthesized in a continuous fashion, while the lagging strand is synthesized in short segments called Okazaki fragments. 4. In the process of transcription, what is the role of RNA polymerase? A) It synthesizes a complementary RNA strand from a DNA template.