How many sentence are correct?
$(1)$ The trophic levels in $GFC$ are unlimited
$(2)$ Organisms at each trophic level depend on those at the higher trophic level for their energy demands.
$(3)$ Plants capture only $2 -10$ percent of $PAR$.
$(4)$ All organisms are dependent for their food on producers, either directly or indirectly.
$3$
$2$
$4$
$1$
$A$ : Detritus food chain begins with detritus.
$R$ : Detrivores like fungi and bacteria are major decomposers in such food chains.
$...A...$ is required for higher primary productivity. $...B...$ have the lowest primary productivity as the soil is deficient in moisture.
Choose the correct option for $\mathrm{A}$ and $\mathrm{B}$
Abyssal zone of oceans is characterized by
Ecosystem creates
In an ecosystem, the insectivorous plants are placed in