1. 12.3
DNA Replication

2. Copying DNA
DNA separates into 2 strands – each serving as template for new strands
Point at which DNA splits = Replication Fork
Enzyme (helicase) breaks H bonds and untwists DNA
Enzyme (DNA Polymerase) moves complementary nucleotides in place to bond properly

4. **mutations can occur – ex. Base left out or inserted
Caused by mutagens (environmental agents that cause mutations)
DNA Polymerase “proofreads”

6. Telomeres = DNA at tip of chromosome
Enzyme (telomerase) add short segments of DNA so info is not lost