Tropical dry deciduous forests, tropical moist deciduous forests and tropical thorn forests.

The technology used to run vehicles on dual mode like petrol or compressed natural gas is said to be hybrid vehicle technology. These vehicles runs on either petrol or CNG. As CNG is clean and green fuel so it is helpful to reduce environmental pollution and also to conserve petrol, fossil field.

1. Discharging thermal waste into a waterbody elimates or reduces the number of organisms sensitive to high temperature.
2. It may enhance the growth of plants and fish in extremely cold areas, but still cause damage to the indigenous flora and fauna.

Biomagnification is increase in the concentration of certain toxic substances at successive trophic levels; this happens because these substances can neither be metabolised nor excreted, but get accumlated and passed on to the next higher trophic level, e.g Mercury and DDT.

(i) Irreparable computers and (ii) other electronic gadgets.
(i) Incineration and (ii) burying in the landfills.
(a) In developing countries, they are recycled involving manual labourers.
(b) In developed countries, they are recycled in specifically built chambers, without involving manual labourers.

(a) Hot spots are the regions of rich biodiversity which have been declared sensitive due to direct or indirect interference of human activities
(b) Four main criteria are-
(i) Rich species diversity
(ii) Number of endemic species
(iii) Degree of threat in terms of habitat loss, and
(iv) Degree of exploitation.
(c) Western ghats and Eastern Himalayas.

(a) BOD - Biochemical Oxygen Demand
(b) It indicates the addition of lot of organic matter; micro-organisms involved in the biodegradation of organic matter in the biodegradation of organic matter in the water body consume a lot of oxygenand as a result, There is a sharp decline in the dissolved oxygen content downstream from the point of addition of effulent from the factory.
This causes mortality of fish and other aquatic organisms.

(a) In the absence of electrostatic precipitator, the particulate pollutants and gaseous pollutants of the exhaust will get into atmosphere as otherwise 99% of the particulate matter is absorbed by ESP. These pollutants cause respiratory disorders.
(b) Following are the general steps to reduce vehicular air pollution:
1. Phasing out of old vehicles.
2. Use of unleaded petrol and low sulphur petrol and diesel.
3. Use of catalytic converters in vehicles.
4. Application of Euro II norms for vehicles.

(i) Deforestation by clearing forest area for cultivation forest area for cultivation of crops, grazing the cattle, felling of trees for timber etc.
(ii) Overgrazing, that leads to soil erosion in the absences to hydrological cycle, by deforestation.

(i) Sleeplessness
(ii) Increased rate of heart beat
(iii) Altered breathing pattern.
(iv) Stress.
(v) Very high sound levels > 150 dB can cause damage to eardrum and permanent loss of hearing.
(iv) Chronic exposure to low level noise may also cause damage to hearing abilities.

Radioactive wastes
1. Radioactive waste is an extremely potent pollutant.
2. The radiation given by the nuclear waste causes mutations and hence is extremely damaging to living organisms.
3. At high doses, the nuclear radiation is lethal and at low doses, it causes cancer.
4. The storage of radioactive waste after sufficient pre-treatment is done in suitably shielded containers buried within the rocks, about 500 m deep below earth's surface.

Electrostatic precipitator
1. It is the most widely used method for removal of particulate matter; about 90% of particulate matter is removed from the exhaust of thermal power plants.
2. It has electrode wires and a stage of collecting plates.
3. The electrode wires are maintained at several thousand volts, which produce a corona that releases electrons.
4. These electrons get attached to the (dust) particles and give them a net negative charge within a very small fraction of a second
5. The collecting plates are grounded and hence attract the charged particles.
6. The velocity of air between the plates must be low enough to allow the particles to fall on them.