Biochemical Oxygen Demand (BOD) in a river water:
Remains unchanged when algal bloom occurs.
Has no relationship with concentration of oxygen in the water .
Gives a measure of Salmonella in the water .
Increases when sewage gets mixed with river water .
The maximum biomagnification would be in which of the following in case of aquatic ecosystem ?
Fishes
phytoplanktons
Birds
Zooplankton
Escherichia coli is used as an indicator organism to determine pollution of water with:
Industrial effluents
Pollen of aquatic plants
Heavy metals
Faecal matter
Green-house effect refers to
production of cereals
cooling of earth
trapping of UV rays
warming of earth
In which one of the following habitats does the diurnal temperature of soil surface vary most?
Shrub land
Forest
Desert
Grassland
Relative Biological Effectiveness (RBE) usually refers to the damages caused by
low temperature
high temperature
radiation
pollution
In 1984, Bhopal gas tragedy was caused due to the leakage of:
Potassium isocyanate
Sodium monoxide
Sodium thiocyanate
Methyl isocyanate
What is the intensity of sound in normal conversation ?
10-20dB
30-60dB
70-90dB
120-150dB
Quercus species are the dominant component in:
Temperate deciduous forests
Alpine forests
Scrub forests
Tropical rain forests
What is BOD ?
The amount of O2 utilized by organisms in water
The amount of O2 utilized by micro-organisms for decomposition
The total amount of O2 present in water
All of the above