Section 8-2B: DNA Replication Chapter 8: DNA and RNA Section 8-2B: DNA Replication

DNA Replication If the two strands separate, the sequence of bases on each strand can be used as a template to form an exact duplicate Replication occurs during the S phase of the cell cycle and is semiconservative Carefully controlled by enzymes Strands are separated, new strands created by DNA polymerase

DNA and Chromosomes In eukaryotes, DNA is contained in chromosomes in the nucleus Chromosomes are DNA and proteins (more protein than DNA) Chromatin is the material that makes up chromosomes

DNA and Chromosomes Histones are proteins that bind directly to DNA Histone + DNA wrapped around it = nucleosome Nucleosomes help package DNA into chromosomes (also aid in transcription) The DNA in a single chromosome may be 10,000X longer than the chromosome itself

Animations http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter14/animations.html# http://207.207.4.198/pub/flash/24/menu.swf http://www.pbs.org/wgbh/nova/genome/dna.html#