DNA Replication IAN pg. 97. MAIN IDEAS DNA Helicase DNA Polymerease Base Pairing Chromatids Centromere. Objective: Identify and Define the parts of DNA using notes, lecture, collaboration and origami . A. DNA Helicase enzyme untwists and unzips DNA exposing base pairs.
IAN pg. 97
Objective:Identify and Define the parts of DNA using notes, lecture, collaboration and origami.
I. DNA Replication before Cell Division (S-Phase)
B. DNA polymerase enzyme attaches new nucleotide bases to create 2 identical copies of DNA.
1. Nucleotides pairing A – TC - G
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C. Following replication 2 genetically identical copies condense into chromosomes
1. Chromatidsarms of the chromosome, genetically identical from DNA replication
2. Centromerecenterprotein structure holds chromatids together.
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Genetically Identical arms
II. DNA remains constant in all cells except in erythrocytes (Red Blood Cells) and sex cells
III. Different Organisms have different amounts of DNA
A. Homo sapiens (Humans) = 46 Chromosomes
B. Myrmecia pilosula (Ant) = 2 Chromosomes
C. Ophioglossom reticulatum (Fern) = 630 Chromosomes