Some toxic substances present in industrial waste water can undergo $.........$ in the aquatic food chain.

Methyl isocyanate gas is used for synthesizing

In a pond,if there is too much wastage,then the $BOD$ of the pond will:

Define/Explain the following terms:
$(i)$ Eutrophication
$(ii)$ Jhum cultivation

$A$ - Micro-organisms involved in the biodegradation of organic matter in the receiving water body consume a lot of oxygen,and as a result,there is a sharp decline in dissolved oxygen in the stream from the point of sewage discharge.
$R$ - $BOD$ decreases when the dissolved oxygen amount decreases in water.

The Bhopal gas tragedy in $1984$ was caused by the leakage of which gas?