Grade 12 · Biology
DNA replication
Why it matters
Copying the genetic code.
Advanced20m readingPrerequisite: None
What is DNA replication?
Short answer
DNA replication is the process by which a cell copies its DNA before dividing, so each new cell gets a complete set. The double helix unwinds, and each strand serves as a template while the enzyme DNA polymerase adds complementary nucleotides (A with T, G with C). The result is two identical DNA molecules, each keeping one original strand — called semiconservative replication.
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Frequently asked questions
- What does "semiconservative" mean?
- Each new DNA molecule keeps one original strand and one newly made strand, so half of each copy is conserved.
- What enzyme builds the new DNA strand?
- DNA polymerase, which adds complementary nucleotides along each template strand.