gen-define-dna-replication-and-give-one-short-worked-example-f64c

Define DNA replication and give one short worked example.

# DNA Replication **Definition:** DNA replication is the biological process by which a cell makes an identical copy of its DNA molecule. The double helix unwinds, and each original strand serves as a template for synthesizing a new complementary strand, resulting in two identical DNA molecules (semi-conservative replication). ## Worked Example **Original DNA sequence (one strand shown 5' to 3'):** ``` 5' - ATGCCGTA - 3' 3' - TACGGCAT - 5' ``` **Step-by-step replication:** 1. **Helicase unwinds** the double helix, separating the two strands 2. **Each strand serves as a template:** - Top strand (5'-ATGCCGTA-3') templates a new strand - Bottom strand (3'-TACGGCAT-5') templates a new strand 3. **DNA polymerase adds complementary nucleotides** (remember: A pairs with T, G pairs with C) **Result - Two identical DNA molecules:** ``` Molecule 1: Molecule 2: 5' - ATGCCGTA - 3' (original) 5' - ATGCCGTA - 3' (new) 3' - TACGGCAT - 5' (new) 3' - TACGGCAT - 5' (original) ``` Each new DNA molecule contains one original strand and one newly synthesized strand.