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DNA Replication. HOW IS DNA COPIED?. s tructure. The __________ of DNA explains how it can be copied. Each strand has all the info needed to construct the __________other half. If strands are separated, _____________ rules allow you to fill in the complementary bases. matching.
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DNA Replication
HOW IS DNA COPIED? structure The __________ of DNA explains how it can be copied. Each strand has all the info needed to construct the __________other half. If strands are separated, _____________ rules allow you to fill in the complementary bases. matching base-pairing
What is the Complementary Strand? G T A C T T G C C A
What is the Complementary Strand? G T A C T T G C C A C A T G A A C G G T
DNA Replication • DNA copies itself exactly, every time the cell divides • This process is called replication
Replication: • Why? • When cells replicate, each new cell needs its own copy of DNA. • Where? • Nucleus in Eukaryotes. • Cytoplasm in Prokaryotes • When? • S phase of interphase in the cell cycle • How?
Steps in Replication • 2 strands unwind • New nucleotides are added to complement the template (original) strands • Strands separate and rewind into 2 molecules (each with 1 old and 1 new strand)
Sites where strand separation and replication occur are called _____________ replication forks Original strand DNA polymerase New strand Growth DNA polymerase Growth Replication fork Replication fork Nitrogenous bases New strand Original strand
DNA Replication 1 old + 1 new strand = semiconservative replication
DNA Replication • Can replicate in 3 minutes (happens at many points at the same time) • Cell proofreads and repairs most mistakes (mutations)