Final answer:
Soil is the unconsolidated portion of the Earth's crust that supports plant life. The idealized soil profile consists of different horizons, including the topsoil (A horizon), subsoil (B horizon), and soil base (C horizon).
Step-by-step explanation:
Soil is the unconsolidated portion of the Earth's crust that supports plant life. It is made up of debris resulting from the weathering of rocks and contains organic matter and living organisms. The fragments of rock may range in size from largish lumps to fine clay.
An idealized soil profile consists of different horizons or layers. The topsoil, known as the A horizon, consists of a mixture of organic material and inorganic products of weathering. The subsoil or B horizon is an accumulation of fine material that has moved downward, resulting in a dense layer in the soil. Beneath the B horizon lies the soil base or C horizon, which includes the parent material and organic and inorganic material that forms the soil.