Question
Description acceptable. Hoogsteen (“HOHG-stain”) base pairing allows B-form DNA to take on this characteristic by forming an alternative adenine–thymine bond. For 10 points each:
[10m] Name or describe this characteristic sometimes observed in satellite DNA that may cause genetic instability by interfering with transcription. A disproven theory posited by Linus Pauling claimed that DNA has this structural characteristic.
ANSWER: triple helix [accept triple-stranded DNA or RNA; accept H-DNA or Triplex-DNA]
[10e] Karst Hoogsteen reported his namesake base pairing by observing an alternative one of these interactions between adenine and thymine. These intermolecular interactions are named for the lightest element.
ANSWER: hydrogen bonds [or H-bonds]
[10h] Hoogsteen base pairs also allow for the formation of G-quadruplex secondary structures, which are useful in the design of these artificial oligomers that target a specific ligand. These molecules are produced in a technique called SELEX.
ANSWER: aptamers
<MS, Biology>
Summary
| Great Lakes | 2025-02-01 | Y | 6 | 13.33 | 100% | 33% | 0% |
| Lower Mid-Atlantic | 2025-02-01 | Y | 1 | 20.00 | 100% | 100% | 0% |
| Midwest | 2025-02-01 | Y | 5 | 26.00 | 100% | 100% | 60% |
| Northeast | 2025-02-01 | Y | 3 | 16.67 | 100% | 33% | 33% |
Data
| Carnegie Mellon B | Carnegie Mellon A | 0 | 10 | 0 | 10 |
| Case Western A | Michigan A | 0 | 10 | 0 | 10 |
| Michigan B | Ohio State A | 0 | 10 | 0 | 10 |
| Michigan C | Case Western B | 10 | 10 | 0 | 20 |
| Kenyon | Michigan D | 0 | 10 | 0 | 10 |
| Ohio State B | Michigan State | 10 | 10 | 0 | 20 |
| Virginia A | Virginia Tech A | 10 | 10 | 0 | 20 |
| Chicago B | Illinois C | 10 | 10 | 0 | 20 |
| Illinois A | Chicago D | 10 | 10 | 10 | 30 |
| WashU A | Indiana A | 10 | 10 | 10 | 30 |
| Indiana B | Chicago A | 10 | 10 | 0 | 20 |
| WashU B | Missoui S&T | 10 | 10 | 10 | 30 |
| Brandeis B | Harvard A | 0 | 10 | 0 | 10 |
| Brandeis A | Harvard B | 0 | 10 | 0 | 10 |
| MIT A | Brown A | 10 | 10 | 10 | 30 |