A. Biotic oxygen deduction
B. Base of degradation
C. Biotic oxide demand
D. Biological oxygen demand
Pollution
Pollution
A. Cadmium
B. Zinc
C. Lead
D. All of the above
A. Decreasing O2
B. Reducing photosynthesis
C. Competing with CO2
D. Being toxic to chloroplasts
A. River is polluted
B. River is not polluted
C. River is day
D. None of these
A. CO2
B. SO2
C. H2
D. CO
A. Hole in ozone layer
B. Decrease in the ozone layer in troposphere
C. Decrease in thickness of ozone layer in stratosphere
D. Increase in the thickness of ozone layer in troposphere
A. CO
B. CO2
C. C
D. SO2
A. Present in water
B. Utilized by organisms in water
C. Utilized by micro-organisms for decomposition
D. Demanded by the producers for the production of food
A. DDT
B. Aluminum foil
C. Domestic wastes
D. Mercury slats
A. Organic matter
B. Microbes
C. Both (a) & (b)
D. None of these