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Unit 6

6.1 DNA and RNA Structure

1 min readjune 4, 2020


Lani Himegarner

AP Biology 🧬

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🧬 The Replication Process

Genetic information is stored within DNA and RNA. It's then passed onto the next generation through replication. The replication process is similar in both prokaryotes (cells without nuclei) and eukaryotes (cells with nuclei), though there are a few differences in how the information is stored. 

Prokaryotes and Eukaryotes

Prokaryotes will usually have circular chromosomes, while eukaryotic organisms will have linear chromosomes. Both can contain plasmids, which are double-stranded, circular molecules that also store DNA.

Nucleotide Base Pairing

One of the differences in the replication process is nucleotide base pairing. In Eukaryotes, Adenine always pairs with Thymine (A-T). However, Thymine does not exist in RNA, so Adenine will pair with Uracil instead (A-U).

Image courtesy of LumenLearning.

In both Eukaryotes and Prokaryotes, Cytosine pairs with Guanine (C-G). Note that Guanine and Adenine are purines, which are characterized by their double-ring structure. Cytosine, Thymine, and Uracil are pyrimidines, which have single ring structures.
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