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

Which of the following is a primary consumer in a maize field ecosystem?

Arrange the stages of hydrarch succession in the correct sequence.

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

Provide information about the aquatic weed known as the 'Terror of Bengal'.

Choose the correct sequence of True $(T)$ and False $(F)$ statements:
$(1)$ Zooplanktons are primary producers in an aquatic ecosystem.
$(2)$ Decomposition is largely an oxygen-requiring process.
$(3)$ In a natural ecosystem, fishes, wolf, etc., are carnivores.
$(4)$ The amount of energy decreases at each successive trophic level.