account for the following:

• combustion of fossil fuels increases the amount of suspended particles in air.
• flow of energy is undirectional whereas biogiochemical transfer is cyclic.

Combustion of fossil fuels produces some important pollutants like unburnt carbon particles. The increase in the levels of these particles results in smog. Smog contains toxic mixture of air pollutants like sulphur dioxide, nitrogen oxides, ozone other volatile organic compounds. The air pollutants from smog cause serious problems to senior citizens, children and people with heart and lung problems leading to emphysema, bronchitis, asthma. Hence combustion of fossil fuels increases the amount of suspended particles in air.

Energy is transformed from one level to another, which results in the large amount of energy loss. The energy lost cannot be restocked again in the atmosphere. Hence energy flow is always unidirectional. But biochemical particles are never lost in the biochemical cycle and are replenished.