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12.3 DNA Replication
Miller & Levine Biology
Before a cell divides, its DNA must first be
copied. (happens during the S phase)
Strands are said to be complementary
Each DNA strand has all info needed to reconstruct the other half because each base only pairs with one other base
duplication the DNA
DNA molecule separates into two strands and
produces two new complementary strands
Each strand of the double helix of DNA serves as a
template for each new strand
separating hydrogen bonds to form a replication fork
base pairing rules
followed while DNA is replicated (A-T & C-G)
Result of Replication
2 DNA molecules identical to eachother, each molecule has an original strand and a new strand
an enzyme that joins individual nucleotides to produce a new strand of DNA
DNA at the tips of chromosomes that are difficult to replicate, use enzyme (telomerase) to speed it up
What is replication carried out by?
a series of enzymes
What bonds are between base pairs?
Prokaryotic cells during replication
Starts at a single point and travels in both directions until the whole circular chromosome is copied
Eukaryotic cells during replication
begins at dozens or even hundreds of places on the DNA and goes in both directions until each chromosome is completely copied
Issues with replication
damaged regions of DNA is replicated and changes base sequence that alters genes and may produce serious consequences