The process by which a DNA molecule builds an exact duplicate of itself.

The process by which a DNA molecule builds an exact duplicate of itself.

• A. Transcription
• B. Replication
• C. DNA Synthesis
• D. DNA Replication

Answer: (D)

DNA replication is the process by which a DNA molecule makes an exact copy of itself. During replication the two strands of the double helix separate, and each serves as a template for synthesizing a new complementary strand. This semi-conservative mechanism means each new molecule has one old strand and one newly made strand, preserving the genetic information. Enzymes orchestrate the steps: helicase unwinds the helix, primase lays down RNA primers, DNA polymerase adds nucleotides in the 5' to 3' direction to form the new strands, and ligase seals any gaps on the lagging strand. Transcription, by contrast, creates RNA from DNA, not a DNA copy. DNA synthesis is a broader term that can refer to any DNA synthesis event, not specifically the genome-wide duplication described here. Therefore, naming the exact genome-duplication process as DNA replication best fits the description.

DNA replication is the process by which a DNA molecule makes an exact copy of itself. During replication the two strands of the double helix separate, and each serves as a template for synthesizing a new complementary strand. This semi-conservative mechanism means each new molecule has one old strand and one newly made strand, preserving the genetic information. Enzymes orchestrate the steps: helicase unwinds the helix, primase lays down RNA primers, DNA polymerase adds nucleotides in the 5' to 3' direction to form the new strands, and ligase seals any gaps on the lagging strand. Transcription, by contrast, creates RNA from DNA, not a DNA copy. DNA synthesis is a broader term that can refer to any DNA synthesis event, not specifically the genome-wide duplication described here. Therefore, naming the exact genome-duplication process as DNA replication best fits the description.