Which description best summarizes DNA replication?

Which description best summarizes DNA replication?

• A. DNA helix unwinds; hydrogen bonds break; each strand serves as a template; complementary bases pair; sugar-phosphate backbone forms; DNA polymerase catalyzes.
• B. DNA remains double-stranded and is transcribed directly into protein.
• C. RNA polymerase replicates DNA by forming a new strand.
• D. Histones condense DNA and prevent replication.

Answer: (A)

DNA replication is the process where the double helix is unwound, hydrogen bonds between base pairs break, and each parental strand serves as a template for a new complementary strand. Nucleotides pair according to base rules (A with T, G with C), and the sugar-phosphate backbone of the new strands is formed by DNA polymerase-synthesized phosphodiester bonds. This creates two identical DNA molecules, each with one old strand and one new strand (semi-conservative replication). The description captures the essential steps: unwinding, template-directed synthesis, base-pair fidelity, backbone formation, and enzymatic catalysis by DNA polymerase. The other options describe transcription or chromatin effects rather than replication, so they don’t fit.

DNA replication is the process where the double helix is unwound, hydrogen bonds between base pairs break, and each parental strand serves as a template for a new complementary strand. Nucleotides pair according to base rules (A with T, G with C), and the sugar-phosphate backbone of the new strands is formed by DNA polymerase-synthesized phosphodiester bonds. This creates two identical DNA molecules, each with one old strand and one new strand (semi-conservative replication). The description captures the essential steps: unwinding, template-directed synthesis, base-pair fidelity, backbone formation, and enzymatic catalysis by DNA polymerase. The other options describe transcription or chromatin effects rather than replication, so they don’t fit.