Bio 1 Notes – Chapter 12.2 DNA Structure and Replication
DNA is a double helix. When it copies (_____________________), parent strands of DNA
separate, serve as templates, and produce DNA molecules that have one strand of ____________
and one strand of _________________. This is called _______________________________.
Stages of Semiconservative Replication:
1) ___________________________
 DNA __________________ unwinds and unzips the double helix.
 The hydrogen bonds between the two strands ________________
 Single-strand binding proteins keep the strands separate
 RNA __________________ adds a short segment of RNA on each strand
2) _______________________________
 DNA _________________ adds nucleotides to each strand (A with T, C with G)
 One strand is copied continuously (_______________ strand)
 Other strand (________________ strand) is copies in pieces. The pieces, called
_____________________ fragments, are later joined by DNA _______________.
3) _______________________________
 DNA polymerase removes RNA primer and replaces with DNA
 Hydrogen bonds reform between the strands, and the double helix reforms
Prokaryotic Cell DNA
 _____________________ DNA molecule
 Found in __________________
 _____________ total nucleotide bases than eukaryotic DNA
 Replication starts in one place only
Eukaryotic Cell DNA
 ______________ DNA molecules
 Found in _______________
 Can have ______________ more bases than prokaryotic DNA
 Highly ______________________________
 Replication starts in multiple places at the same time
Section 12-2
New strand
Original
strand
DNA
polymerase
DNA Replication
Growth
DNA
polymerase
Growth
Replication fork
Replication fork
New strand
Original
strand
Nitrogenous
bases