1. Mohan has observed that the water logged areas in his neighbourhood produces a particular odour. (a) Name the gas that is produced by the marshy areas and the microorganisms responsible for that. (1) (b) Could this gas be an environmental threat? Why?

Dear student,

a) The gas that is produced in the marshy area is methane and the organism responsible for the production of this gas is methanogen eg., Methanococcus, Methanobacterium.
b) Yes, this gas could be an environmental threat because methane is one of the components of green house gases. Along with carbon dioxide, it also helps in thinning of the ozone layer and ultimately causing global warming. So it is a threat to earth's ecosystem.

Regards.