Q15 - Structural Changes Along Rhizophore Orders in Rhizophora mangle
Scientists measured length and height of rhizophores of the mangrove plant (Rhizophora mangle, Fig.Q15A). They also made cross sections of rhizophores and observed their anatomical characteristics. The results are shown in Q15B and Q15C.
Figure 1.
Using the information and data, determine which of the statements are true or which are false.
A. There are monotonic decreases in rhizophore height and the length/height proportion in the rhizophores as a function of the rhizophore order.
B. Within first-order rhizophores, the xylem proportion in the cross-section is larger when closer to the main stem, and decreases progressively as the rhizophore approached the ground while increasing the proportion of bark and pith.
C. When rhizophore order changes from 1 to 5, bark and pith proportion decreases, while xylem proportion increases.
D. The supportive function is likely enhanced in the first-order rhizophores, with lower length/height proportion, and higher proportion of xylem compared with bark and pith.
Question reproduced from IBO 2016, Theoretical Paper A, licensed under CC BY-NC-SA 4.0 - attributed to the International Biology Olympiad. Open the full exam PDF · Community solutions (unofficial)