Identify the correct type of food chain.
Dead animal $\rightarrow$ Blow fly maggots $\rightarrow$ Common frog $\rightarrow$ Snake

$A$: Estuary constitutes one of the most productive ecosystems.
$R$: It represents a transition zone between two populations of a species.

In which trophic level does the Sparrow belong as a consumer?

Given below are two statements:
Statement $I$: In an ecosystem,there is a unidirectional flow of energy from the sun through producers to consumers.
Statement $II$: Ecosystems are exempted from the $2^{nd}$ law of thermodynamics.
In the light of the above statements,choose the most appropriate answer from the options given below:

Choose the incorrect statement.

Choose the incorrect sentence from the following.