Transfer of material and energy from one ecosystem to another ecosystem is best exemplified 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?

In a typical terrestrial ecosystem,which of the following statements regarding population size is correct?

The phosphates remain outside the natural cycle for a long time:

The energy obtained from fossil fuels is essentially a product of which of the following?

The importance of an ecosystem lies in its function of: