What happens to the two strands during DNA replication?

What happens to the two strands during DNA replication?

• A. The two strands separate and each strand becomes a template for a new complementary strand.
• B. The two strands remain bound and are copied as a single unit.
• C. RNA primers drive the entire process without strand separation.
• D. The original strands are degraded after copying.

Answer: (A)

During DNA replication, the double helix unwinds and the two strands separate. Each separated strand serves as a template for a new complementary strand, so you end up with two identical double-stranded DNA molecules—each containing one original strand and one new strand. This semi-conservative outcome arises because polymerases add nucleotides based on base-pairing rules while helicase unwinds the helix and RNA primers provide starting points. The original strands aren’t degraded; they remain part of the daughter molecules.

During DNA replication, the double helix unwinds and the two strands separate. Each separated strand serves as a template for a new complementary strand, so you end up with two identical double-stranded DNA molecules—each containing one original strand and one new strand. This semi-conservative outcome arises because polymerases add nucleotides based on base-pairing rules while helicase unwinds the helix and RNA primers provide starting points. The original strands aren’t degraded; they remain part of the daughter molecules.