Question

role of living organisms in formation of soil

Answer 1

after millions of years they form fossils

Answer 2

Plants, animals and micro-organisms (fungi and bacteria) all affect soil formation by producing or contributing to humus production.

The amount of humus in a soil is a result of how much plant material has been incorporated into it. If vegetation is sparse a soil will be low in humus and less fertile.

Grasses have fibrous root systems that spread throughout the tiny pores of the soil - as the roots die and decay the soil becomes well supplied with humus.