The provided diagram represents:

They are not included in decomposers.

Match the following columns correctly:

Column-$I$	Column-$II$
$(i)$ Producers	$(P)$ Primary consumers
$(ii)$ Herbivores	$(Q)$ Net primary productivity
$(iii)$ Carnivores	$(R)$ Primary trophic level
$(iv)$ Top carnivores	$(S)$ Secondary productivity

The bulk fixation of carbon through photosynthesis takes place in

Some of the nutrient cycles are labelled as below:
$I$. Sulphur cycle
$II$. Phosphorus cycle
$III$. Carbon cycle
$IV$. Nitrogen cycle
Of these,the sedimentary cycle is represented by:

Read the following statements carefully and answer the question:
$(1)$ Pyramids of number and biomass can be upright or inverted in an ecosystem.
$(2)$ Phosphorus and sulfur are sedimentary cycles.
$(3)$ The largest reservoir of carbon on Earth is found in the oceans.
$(4)$ The structural and functional unit of ecology is the ecosystem.
Which of the above statements are correct?