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

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

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.

Which of the following is the largest root parasite

• Rafflesia

• Monotrapa

• Areuthobium

• Pistia

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%

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

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.

Photochemical smog formed in congested metropolitan cities mainly consists of:

• Hydrocarbons, ozone and SO_x

• Hydrocarbons, SO₂ and CO₂

• Smoke, peroxyacetyl nitrate and SO₂

• Ozone, peroxyacetyl nitrate and NO_x

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.