Acid rain is due to increase in atmospheric concentration of :
Ozone
CO2 and CO
SO3 and CO
SO2 and nitrogen oxide
D.
SO2 and nitrogen oxide
Acid rain is any form of precipitation with acidic components, such as sulfuric acid or nitric acid that fall to the ground from the atmosphere in wet or dry forms. Both sulphur dioxide (SO2) and nitrogen oxide (NO2) are converted to acids when they combine with water vapour in the atmosphere. These acids return into earth as either wet deposition (acid rain or snow) or dry deposition (sulphate and nitrate salts).
One of the major difficulties in the biological control of insect pests is the :
practical difficulty of introducing the predator to specific areas
method is less effective as compared with the use of insecticides
predator does not always survive when transferred to a new environment
predator develops a preference to other diets and may itself become a pest
Photochemical smog formed in congested metropolitan cities mainly consists of:
Hydrocarbons, ozone and SOx
Hydrocarbons, SO2 and CO2
Smoke, peroxyacetyl nitrate and SO2
Ozone, peroxyacetyl nitrate and NOx
The production and maturation of sperm in testes is known as :
oogenesis
sporogenesis
gametogenesis
spermatogenesis
The formation of gametophyte, from sporophyte, without spore formation or without meiosis is known as :
apospory
apogamy
parthenogenesis
none of these
Anemophillous flowers have :
sessile stigma
small and smooth stigma
coloured flower
large and feathery stigma
The true statement about 'green-house effect' is that it is caused by :
CO2 only
SO2 only
CO2 and SO2
CO2, CFC, CH4 and NO2 gases