Why dose the cell membrane of the tube worm stop the flow of excess salt in to its body?

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.

Why is excretion necessary to maintain homeostasis?

Diagram of the evolution of land plants?