Ecosystems — BIOLOGY STD 12 Science — Question

$I$. Insulin for curing diabetes, used to be extracted from the pancreas of slaughtered pig and cattle

$II$. Animal insulin is slighty different from the human insulin

$III$. Animal insulin causes some undesirable side effects such as allergy

$IV$. Bacteria cannot be made to synthesise insulin from its gene because of the presence of introns

Choose the correct option

$(1)$ 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.