All Subjects



AP Bio



Unit 6

6.1 DNA and RNA Structure

1 min readnovember 29, 2021


Lani Himegarner

AP Biology 🧬

Bookmarked 9.6k • 333 resources
See Units

🧬 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.
Check out the AP Bio Unit 6 Replays or watch the 2021 Unit 6 Cram


Was this guide helpful?

Fiveable logo
Join Fiveable for free
Create a free account to bookmark content and compete in trivia
Hours Logo
Studying with Hours = the ultimate focus mode
Start a free study session
Browse Study Guides By Unit
📆Big Reviews: Finals & Exam Prep
✍️Free Response Questions (FRQ)
👏General Review
🧐Multiple Choice Questions (MCQ)
🧪Unit 1: Chemistry of Life
🧬Unit 2: Cell Structure and Function
🔋Unit 3: Cellular Energetics
🦠Unit 4: Cell Communication and Cell Cycle
👪Unit 5: Heredity
👻Unit 6: Gene Expression and Regulation
🦍Unit 7: Natural Selection
🌲Unit 8: Ecology
FREE AP bio Survival Pack + Cram Chart PDF
Sign up now for instant access to 2 amazing downloads to help you get a 5