Answer in brief.

What do you mean by biological weathering?

Weathering is the disintegration, breaking down and decomposition of components in the earth's crust through the action of natural or other agents. Weathering can occur due to exposure to the earth's atmosphere. Weathering is controlled and determined by various factors like temperature, rainfall, vegetation and movements of other components in the earth's crust. Glacier, wind, rivers, ocean waves and groundwater are the major agents of weathering. Weathering can be physical, chemical or biological.

Biological weathering occurs because of the actions of the flora, fauna and human interferences. It results in the decomposition of the components due to the biological processes involved with the expansion of the activities of the living organisms. The growth of plants, the penetration of their roots, diffusion of rotten plant and animal cells, burrowing of animals and many other human interferences are the major causes of biological weathering.