Which finding, if true, would most directly support the hypothesis pr…

|Question 37Verbal

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Some toothpastes contain titanium dioxide nanoparticles (

T i O_{2}

-NPs) which can leach into waterways and soils via wastewater. In a 2015 study, Adeline Bourgeault and colleagues found that

T i O_{2}

-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

T i O_{2}

-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?

In comparable environments, D. polymorpha and C. carpio display comparable rates of

T i O_{2}

-NP uptake.

Compared with C. carpio, D. polymorpha can tolerate significantly higher

T i O_{2}

-NP concentrations without displaying any negative effects.

It is easier to detect low and harmless concentrations of

T i O_{2}

-NPs in D. polymorpha than it is to detect high and harmful concentrations of

T i O_{2}

-NPs in C. carpio.

T i O_{2}

-NP concentrations in D. polymorpha tend to vary more from individual to individual than do

T i O_{2}

-NP concentrations in C. carpio when the species are exposed to similar levels of

T i O_{2}

-NPs.