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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
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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#