A lake with an inflow of domestic sewage rich in organic waste may result in
drying of the lake very soon due to algal bloom
an increased production of fish due to lot of nutrients
death of fish due to lack of oxygen
increased population of aquatic food web organisms.
C.
death of fish due to lack of oxygen
When BOD levels are high, dissolved oxygen (DO) levels decrease because the oxygen that is available in the water is being consumed by the bacteria. Since less dissolved oxygen is available in the water, fish and other aquatic organisms may not survive.
Minamata disease was caused due to the consumption of
sea food containing lot of cadmium
fish contaminated with mercury
oysters with lot of pesticide
sea food contaminated with selenium.
An artificial pacemaker is implanted subcutaneously and connected to the heart in patients
having 90% blockage of the three main coronary arteries
having a very high blood pressure
with irregularity in the heart rhythm
suffering from arteriosclerosis.
Assertion : Presently, the global atmosphere is warming up.
Reason : The depletion of stratospheric ozone layer has resulted in increase in ultraviolet radiations reaching the earth.
If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
If both Assertion and Reason are true but the Reason is not the correct explanation of the assertion
If Assertion is true but Reason is false.
If both Assertion and Reason are false
In almost all Indian metropolitan cities like Delhi, the major atmospheric pollutant(s) is/are:
suspended particulate matter (SPM)
oxides of sulphur
carbon dioxide and carbon monoxide
oxides of nitrogen
Assertion: Agricultural output increased several times after introduction of DDT.
Reason: DDT was the first insecticide used on a wide scale.
If both Assertion and Reason are true and Reason is the correct explanation of Assertion
If both Assertion and Reason are true but Reason is not the correct explanation of Assertion
If Assertion is true but Reason is false
If both Assertion and Reason are false.
Drinking of mineral water with very low level of pesticides (about 0.02 ppm) for long periods may:
produce immunity against mosquito
cause leukemia (blood cancer) in most people
cause cancer of the intestine
lead to accumulation of pesticide residues in body fat
The correct match of atmospheric gases is :
Nitrogen - 0.03%; Oxygen - 78.08%; Argon - 0.93%; CO2 - 20.95%
Nitrogen - 78.08%; Oxygen - 20.95%; Argon - 0.03%; CO2 - 0.03%
Nitrogen - 0.03%; Oxygen - 78.08%; Argon - 20.95%; CO2 - 0.93%
Nitrogen - 78.08%; Oxygen - 20.95%; Argon - 0.93%; CO2 - 0.03%
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