Which symbiotic life forms can grow on stones and help in the formation of soil? Write the mode of their action for making soil from rocks.

(N/A) $(i)$ Lichens are the symbiotic life forms that can grow on bare rocks.
$(ii)$ They secrete certain organic acids while growing on the surface of rocks.
$(iii)$ These acids cause the rock surface to weather,creating small cracks and crevices.
$(iv)$ Over time,these cracks widen due to the accumulation of dead organic matter and the action of water and wind,eventually breaking the rock into smaller particles to form soil.