Question

which element can biomagnify and bioaccumulate in ecosystems? mercury helium

Explanation:

Mercury is a heavy metal that can enter ecosystems through various sources like industrial emissions. It can be absorbed by organisms (bioaccumulation). As organisms are consumed by others in the food chain, the concentration of mercury increases (biomagnification). Helium is a noble gas and does not have the properties to bioaccumulate or biomagnify in ecosystems.

Answer:

Mercury