Complementary base pairing allows DNA strands to serve as copying templates.
Key knowledge
In semiconservative replication of double-stranded DNA, each parental strand serves as a template for a new complementary strand. Each resulting double helix contains one parental strand and one newly synthesized strand.
Conditions and scope
This describes ordinary cellular double-stranded DNA replication; detailed enzymes and viral replication strategies are outside scope.
Copying is not infallible: proofreading and repair correct many errors, while uncorrected changes can become mutations.
Sources · 3
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Mary Ann Clark, Matthew Douglas and Jung Choi — OpenStax, Rice University2 sources
Textbook account of the semiconservative model, Meselson–Stahl observations and error correction; those experiments were not repeated.
2026-10-10 · English template/strand distinction checked against section 14.3 and the bounded copying-error qualification against section 14.6.
Foundational review
2026-10-10 · Fresh primary-source inspection of the complete compact record, including every statement, equation, quantity and material condition, followed by independent AI editorial review. This check does not certify all linked lessons or every passage of every cited publication.
Sources from other places
Agreement within this scope
Semiconservative template copying and one old/new strand per daughter helix.
Copying mechanism and copying accuracy are separate questions.
In semiconservative replication of double-stranded DNA, each parental strand serves as a template for a new complementary strand. Each resulting double helix contains one parental strand and one newly synthesized strand.
DNA is a nucleic acid whose sequence of bases carries genetic information. In the usual double helix, sugar-phosphate backbones support bases paired A with T and C with G. DNA sequence can specify protein or functional RNA products.
Complementary DNA strands serve as templates in semiconservative copying.
In semiconservative replication of double-stranded DNA, each parental strand serves as a template for a new complementary strand. Each resulting double helix contains one parental strand and one newly synthesized strand.
In a typical mitotic eukaryotic cell cycle, nuclear DNA is replicated during S phase before mitosis separates sister chromatids into daughter nuclei. Cytokinesis usually divides the cytoplasm into daughter cells. Mitosis and cytokinesis are distinct processes.
Nuclear DNA replication precedes mitosis in the typical mitotic eukaryotic cell cycle.
A mutation is a change in DNA sequence. It can arise during replication or from other processes that alter DNA. Whether a mutation enters subsequent generations depends on the affected cell lineage and the organism's route of reproduction.
Replication can introduce DNA-sequence changes; it is not the sole mutation source.
Replicative DNA polymerases extend a primer's 3′ end while copying a template, synthesizing DNA 5′→3′. Helicase opens the duplex, primase supplies primers, topoisomerases relieve torsional stress and ligase joins processed fragments. Opposite template orientations require continuous leading-strand and discontinuous lagging-strand synthesis at a typical fork.
This supplies the machinery behind semiconservative replication.