Ecological succession on sand is known as:

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

Match the trophic levels with their correct species examples in a grassland ecosystem.

$(a)$ Fourth trophic level	$(i)$ Crow
$(b)$ Second trophic level	$(ii)$ Vulture
$(c)$ First trophic level	$(iii)$ Rabbit
$(d)$ Third trophic level	$(iv)$ Grass

Select the correct option:

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.

The importance of an ecosystem lies in

Which among the following is not a functional unit of the ecosystem?