Question

Given below are four statements each with two blanks.
Select the option which correctly fills up the blank in any two statements.
(i)Bhopal gas disaster took place in _____ 1984 and this day is now observed as the ______ day in India to make the anniversary of the Bhopal gas disaster.
(ii)______ is a biodegradable pollutant while _____ is a non-biodegradable pollutant.
(iii)When pollutants are released from a single point it is called _____ pollution, but when it is over a large area, then it is called _____ pollution.
(iv)______ is the world’s most problematic aquatic weed, introduced in India for its lovely flowers, also called as ______.
(a)(i)December 5, National pollution prevention (iv)Parthenium, the terror of Bengal
(b)(i)December 2, Bhopal gas tragedy (ii)DDT, sewage
(c)(ii)Sewage, DDT (iii)point source, nonpoint source
(d)(iii)Line source, fixed source (iv)Eicchornia, the tiger of Bengal

Answer 1

Hint: Bhopal gas tragedy took place due to the leakage of the deadly methyl isocyanate gas. Biodegradable pollutants are the ones that can be broken down by decomposers whereas non-biodegradable cannot be broken down. The world’s most problematic aquatic weed is also known as the water hyacinth.

Complete answer:
Let us look at all the statements mentioned individually.
(i) Bhopal gas disaster took place on the night of 2-3 December 1984 and this day is now observed as the Bhopal gas tragedy day in India to make the anniversary of the Bhopal gas disaster. This disaster took place due to the gas leak of methyl isocyanate at the Union Carbide India Limited (UCIL) pesticide plant in Bhopal. It is estimated that close to 20,000 people died and thus it is considered one of the world’s worst industrial disasters.
(ii) Sewage is a biodegradable pollutant while DDT is a non-biodegradable pollutant and this is because sewage mostly comprises of organic compounds which can be easily broken down by decomposers but DDT is known as dichlorodiphenyltrichloroethane and it is a pesticide which is non-biodegradable and thus enters the food chain and get biomagnified.
(iii)When pollutants are released from a single point it is called point-source pollution, but when it is over a large area, then it is called non-point source pollution as nonpoint sources come from many places and it is difficult to pinpoint any one particular source.
(iv)Eichhornia is the world’s most problematic aquatic weed, introduced in India for its lovely flowers, also called the ‘Terror of Bengal’ due to the devastation it produced in the ecosystems of Bengal as its natural predator was not present there. Such species are known as invasive species.
So, the correct option is ‘(ii)Sewage, DDT (iii)point source, nonpoint source’.

Note: -A recent gas leak occurred at Visakhapatnam known as the Vizag gas leak which occurred due to the accidental gas leak of styrene at the LG Polymers chemical plant.
-Biomagnification which is also known as bio-amplification is the increase in the concentration of a toxin as we go higher in the trophic levels of a food chain.
-Parthenium is also known as carrot grass and is responsible for causing allergy in people due to its pollen grains.