Question
Answer the following about halotolerance mechanisms evolved by mangrove plans, for 10 points each.
[10h] To take up water under high salinity, mangrove tissues often reduce this energetic quantity by accumulating ions. At and beyond the turgor loss point, this quantity is usually equal to the total water potential.
ANSWER: osmotic potential [or solute potential; prompt on pi or psi-sub-pi, or psi-sub-s]
[10m] Mangrove roots deposit suberin in the radial and transverse cell walls of endodermal cells to form this structure, which acts as a diffusion barrier to prevent salt from entering the apoplast.
ANSWER: Casparian strip [or Casparian band]
[10e] Some mangrove plants simply trap salt by using sodium–proton pumps to concentrate it into these storage organelles. A “central” one of these organelles in plant cells stores water and maintains turgor pressure.
ANSWER: vacuoles (“VACK-yoo-oles”) [accept central vacuole]
<Biology>
Summary
| 2023 ACF Nationals | 04/22/2023 | Y | 13 | 13.85 | 100% | 31% | 8% |
Data
| Duke A | Illinois A | 10 | 0 | 10 | 20 |
| WUSTL B | Ohio State A | 0 | 10 | 10 | 20 |
| Minnesota A | Rutgers A | 0 | 0 | 10 | 10 |
| McGill A | Rutgers B | 0 | 0 | 10 | 10 |
| WUSTL A | Purdue A | 0 | 0 | 10 | 10 |
| Vanderbilt A | Chicago A | 0 | 0 | 10 | 10 |
| Chicago B | Cornell A | 0 | 0 | 10 | 10 |
| Texas A | UC Berkeley B | 0 | 10 | 10 | 20 |
| Yale A | Columbia A | 0 | 10 | 10 | 20 |
| Chicago C | Georgia Tech A | 0 | 10 | 10 | 20 |
| Penn State A | MIT A | 0 | 0 | 10 | 10 |
| Stanford A | NYU A | 0 | 0 | 10 | 10 |
| Houston A | Harvard A | 0 | 0 | 10 | 10 |