MODEL PAPER 4 — BIOLOGY STD 12 Science — Question

$(1)$ 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.

$I.$ increasing $RBC$

$II.$ decreasing binding affinity of haemoglobin

$III.$ increasing binding affinity of haemoglobin

$IV.$ increasing breathing rate

$V.$ decreasing breathing rate

Choose the correct option for given statement

$R$ - The salt concentration is $45 -50$ (parts per thousand) in the sea.