Which of the following organisms convert plant matter into animal matter?

$A$: $A$ stable community should show much variation in year-to-year productivity.
$R$: It must not be resilient to occasional disturbance.

In a pond ecosystem,which organisms can occupy more than one trophic level?

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.

If less light falls on the pond's surface,what is the most likely consequence for the fish population?

From the above given features,how many are associated with primary succession?
Features:
$1$. Occur on newly cooled lava
$2$. Faster succession
$3$. Progress to mesic condition
$4$. Occurs on flooded land
$5$. Slower succession
$6$. Changes in flora only