GEOG 170A1 Lecture Notes - Lecture 6: Thymine, Adenine, Pyrimidine
11 Sep 2015
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Document Summary
Two chains of nucleotides twisted together into a double helix. Contains all inherited info necessary to build an organism. Cells use the order of nucleotide bases in the dna. A nucleic acid monomer consisting of 5 carbon sugars. Amounts of thymine and adenine in dna are the same proportion of adenine and guanine differs among species. Dna in a eukaryotic cell is organized as 1 or more chromosomes. Carries part of all of a cell"s genetic info. During most of the cell"s life ach chromosome consists of 1 dna strand when the cells prepare to divide it duplicates all of its chromosomes. The numbers of chromosomes differ in each species. Dna replication is the energy intensive process by which a cell copies its dna. A cell copies its dna before it reproduces. Dna polymers proofread dna sequences during dna replication. Mistakes are rare in dna replication, but can be fixed. Forms pyrimidine dimers that kink dna strands causes skin cancer.
