Phosphorus of the ocean becomes available to land plants due to:

Match the columns:

Column-$I$	Column-$II$
$(a)$ Decomposers	$(i)$ Bacteria
$(b)$ Primary productivity	$(ii)$ Consumers
$(c)$ Natural ecosystem	$(iii)$ Producers
$(d)$ Secondary productivity	$(iv)$ Forest

Identify $Z$ in the given figure representing the carbon cycle.

Identify the mismatched pair from the given options.

Which of the following statements are correct?
$(a)$ Net primary productivity is available biomass for consumption to heterotrophs.
$(b)$ Secondary productivity is defined as the rate of formation of new organic matter by heterotrophs.
$(c)$ The annual net primary productivity of the ocean is greater than that of land.
$(d)$ Warm and moist environment favours decomposition.

Given below are two statements:
Statement $I$: In an ecosystem,there is a unidirectional flow of energy from the sun through producers to consumers.
Statement $II$: Ecosystems are exempted from the $2^{nd}$ law of thermodynamics.
In the light of the above statements,choose the most appropriate answer from the options given below: