In a food chain of a grassland ecosystem,the top consumers are

Match the following columns:

Column-$I$	Column-$II$
$P$. Herbivores	$I$. Directly dependent on plants
$Q$. Carnivores	$II$. Indirectly dependent on plants
$R$. Saprophytes (Fungi)	$III$. Dependent on dead or decaying matter

Which of the following characteristics can be observed in ecological succession?

Which one of the following is not a function of an ecosystem?

Consider the following four statements $(A-D)$ and select the correct option stating which ones are true $(T)$ and which ones are false $(F)$.
Statements:
$(A)$ Vertical distribution of different species occupying different levels in a community is called stratification.
$(B)$ Net primary productivity minus respiration losses is the gross primary productivity.
$(C)$ Rate of biomass production is called decomposition.
$(D)$ Annual net primary productivity of oceans is $55$ billion tons.

In the carbon cycle,the source of carbon for plants is: