A researcher studies a population of fish kept in an aquarium. The diagram shows the nitrogen cycle in the aquarium.
A high concentration of ammonia is toxic to fish. Every day when the researcher checks the levels of ammonia, nitrites, and nitrates in the aquarium, she finds that the concentration of ammonia is very high while the concentrations of nitrites and nitrates are low.
What should the researcher add to the aquarium to help decrease the concentration of ammonia in the aquarium?
A.
plants
B.
Nitrobacter
C.
Nitrosomonas
D.
food
C. Nitrosomonas
Nitrosomonas is a type of bacteria that helps convert ammonia to nitrites in the nitrogen cycle. By adding Nitrosomonas bacteria to the aquarium, the levels of ammonia can be reduced and subsequently the levels of nitrites and nitrates will increase as part of the natural nitrogen cycle.