The figure shows the biomagnification of $DDT$ in an aquatic food chain. What could be the concentration of $DDT$ in $P$,$Q$,and $R$ respectively?

Which one of the following is not a bioindicator of water pollution?

Consider the following statements:
$(a)$. $40\%$ of the forest has been lost in the tropics.
$(b)$. $JFM$ was introduced in $1965$ by the $UNCED$.
$(c)$. The Bishnoi community belongs to Odisha and played a major role in the conservation of forests.
$(d)$. The Chipko movement started in the Garhwal Himalayas.

The most common pesticide used in India is

Rice fields produce an important greenhouse gas. Name it.

Consider the following statements about eutrophication:
$I.$ Eutrophication is the natural ageing of a water body by nutrient enrichment.
$II.$ The accelerated ageing of lakes due to sewage and agricultural and industrial wastes is called cultural or accelerated eutrophication.
$III.$ The plant nutrients responsible for eutrophication are nitrates and phosphates.
$IV.$ Phosphates and nitrates accelerate the growth of algae which utilize oxygen and may deoxygenate the water enough to kill the fish and other aquatic animals.
Which of the statements given above are correct?