(a) Identify the biogeochemical cycle.

(b) Fill in the blanks: A, B, C and D.

(c) What will happen if the step E does not occur.

(a) The given cycle is Nitrogen cycle because the green plants release ammonia by ammonification. The ammonia released is converted into nitrite which are further converted into other nitrates.

(b)

A—Ammonification; The green plants release ammonia by utilizing nitrogen in soil.

B—Ammonia; released from plants by ammonification.

C—Nitrite; Ammonia is converted into nitrite by nitrifying bacteria Nitrosomonas.

D— Nitrates. Nitrite is further converted into other nitrates by Nitrobacter.

(c)In the absence of setp E, i.e. denitrifying bacteria, atmospheric nitrogen wil not be replenished as nitrates wont be converted into N2 by denitrifying bacteria.