Sponges belong to phylum porifera why

What kind of seafood would you expect to have the highest levels of mercury and why? kelp, because they use the sun to photosynthesize on the bottom trophic level. oysters, because they filter feed on plankton on a lower trophic level. small fish, because they eat plankton on a higher trophic level. sharks, because they feed on organisms on a higher trophic level.

Which of the organisms listed below performs nitrogen fixation? a. legumes b. plants c. bacteria d. fungi

Explain the significance of thesaurus geographicus