Question

some toothpastes contain titanium dioxide nanoparticles (tio₂ - nps), which can leach into waterways and soils via wastewater in a 2015 study, adeline bourgeault and colleagues found that tio₂ - nps can accumulate in the bodies of zebra mussels (dreissena polymorpha). while bioaccumulation of manufactured nanoparticles may be inherently worrisome, it has been hypothesized that tio₂ - np bioaccumulation in invertebrates like d. polymorpha could serve a valuable proxy role, obviating the need for manufacturers to conduct costly and intrusive sampling of vertebrate species—such as common carp (cyprinus carpio), commonly used in regulatory compliance testing—for nanoparticle bioaccumulation, as environmental protection laws currently require. which finding, if true, would most directly support the hypothesis presented in the text? a. in comparable environments, d. polymorpha and c. carpio display comparable rates of tio₂ - np uptake. b. compared with c. carpio, d. polymorpha can tolerate significantly higher tio₂ - np concentrations without displaying any negative effects. c. it is easier to detect low and harmless concentrations of tio₂ - nps in d. polymorpha than it is to detect high and harmful concentrations of tio₂ - nps in c. carpio. d. tio₂ - np concentrations in d. polymorpha tend to vary more from individual to individual than do tio₂ - np concentrations in c. carpio when the species are exposed to similar levels of tio₂ - nps.

Explanation:

The hypothesis is that $TiO_2 - NPs$ bioaccumulation in $D.$ polymorpha can serve as a proxy for that in vertebrates like $C.$ carpio. If they have comparable uptake rates in similar environments, it directly supports the idea that $D.$ polymorpha can act as a substitute for $C.$ carpio in testing. Option B focuses on tolerance, C on detection of different concentrations, and D on variation among individuals, none of which directly support the proxy - role hypothesis.

Answer:

A. In comparable environments, $D.$ polymorpha and $C.$ carpio display comparable rates of $TiO_2 - NP$ uptake.