Agents of biological process of weathering
1. Roots of plants
2. Hooves of animals
3. Earthworm
4. Man

Root of plants: these penetrate the rock resulting in breaking of rocks
Hooves of animals:  trample on rocks and break them
Earthworm: the burrowing activities of earthworm allow water, carbon dioxide, etc. to enter and react with rock.
Man: the activities of man during cultivation help to break rocks
Agents of physical process of weathering
1. Water
2. Wind
3. Temperature
4. Pressure
Water: water react with rock or break rock during erosion
Wind: wind blows rocks against rocks resulting in breakage
Temperature: expansion and contraction of rocks due to temperature causes disintegration of rocks
Pressure: the weight of over laying rocks causes rocks to fall and these results in breakage.