Question

when otters eat urchins, their primary food, sea otters damage the roots of eelgrass plants, preventing the seagrass from vancouver island in canada, the otter population is large and well - established, yet the seagrass meadows are healthier than those found elsewhere. compared to coastal, to explain this, conservation scientist erin foster and colleagues compared the seagrass - based meadows to meadows where otters are absent or were reintroduced only recently, finding that the vancouver island meadows have a more diverse gene pool than the others do. foster hypothesized that damage to eelgrass roots increases the plant’s rate of sexual reproduction, thus, in turn, boosts genetic diversity, which benefits the seagrass’s health overall.
10 mark for review
which finding, if true, would most directly undermine foster’s hypothesis?
a at some sites in the study, eelgrass meadows are found near otter populations that are small and have only recently been reintroduced.
b at several sites not included in the study, there are large, well - established sea otter populations but no eelgrass meadows.
c at several sites not included in the study, eelgrass meadows’ health correlates negatively with the length of residence and size of otter populations.
d at some sites in the study, the health of plants unrelated to eelgrass correlates negatively with the length of residence and size of otter populations.

Explanation:

To undermine Foster's hypothesis (damage to eelgrass roots increases plant's social reproduction, boosting genetic diversity and health), we need a finding that shows eelgrass meadow health isn't related to eelgrass (or otter presence/root damage). Option D states that at some sites, plant health is unrelated to eelgrass, which directly challenges the link between eelgrass - related factors (like root damage from otters) and plant health, thus undermining the hypothesis. Other options either support the relationship (A, B) or relate to otter residence length (C) which is less direct to the hypothesis's core link.

Answer:

D. At some sites in the study, the health of plants unrelated to eelgrass correlates negatively with the length of residence and size of otter populations.