dB is a standard abbreviation used for the quantitative expression of:

1. the density of bacteria in a medium

2. a particular pollutant

3. the dominant Bacillus in a culture

4. a certain pesticide

The two gases making the highest relative contribution to the greenhouse gases are:

1. $C{O}_2$ $and$ $C{H}_4$

2. $C{H}_4$ $and$ $$ $N{O}_2$

3. $\mathrm{CFCs}$ $\mathrm{and}$ ${\mathrm{N}}_2\mathrm{O}$

4. $C{O}_2$ $and$ $N_{2}O$

Chipko movement was launched for the protection of:

1. grasslands

2. forests

3. livestock

4. wet lands

DDT residues are rapidly passed through food chain causing biomagnification because DDT is:

1. lipo soluble

2. moderately toxic

3. non-toxic to aquatic animals

4. water soluble

Steps taken by the Government of India to control air pollution include:

Montreal protocol aims at:

1. reduction of ozone depleting substances

2. biodiversity conservation

3. control of water pollution

4. control of CO₂ emission

Biochemical Oxygen Demand (BOD) in river water:

Global agreement in specific control strategies to reduce the release of ozone-depleting substance was adopted by:

1. Rio de Janeiro Conference

2. The Montreal Protocol

3. The Kyoto Protocol

4. The Vienna Convention

A lake near a village suffered heavy mortality of fish within a few days. Consider the following reasons for this:

Which two of the above were the main causes of fish mortality in the lake?

1. 2, 3
2. 3, 4
3. 1, 3
4. 1, 2