Pests which only feed and oviposit on crop are called
major pests
minor pests
accidental pests
occasional pests
In which stage of its life cycle, the silk moth begins to produce silk fibre?
3rd instar larva
4th instar larva
5th instar larva
Pupa
Which of the following is not a Green-house gas?
N2O
CFC
O3
CO2
C.
O3
The gases responsible for Green-house effect are CO2, CH4, CFCs and N2O. The Green-house gases cause global warming. The CO2 is considered as most dominant factor responsible for Green- house effect.
Increase of BOD in water leads to
increase in the dissolved O2 concentration
decrease in the dissolved O2 concentration
maintenance of dissolved O2 concentration at the same level
no effect on dissolved O2 concentration
Freon gas causing stratospheric O3 depletion is mainly released from
refrigerator
automobile
thermal power plant
steel industry