â¢ The response of the innate system is rapid while that of the adaptive immunity is slow (Over 1-2 weeks). â¢ The innate system has limited and lower potency. In contrast, the adaptive system has high potency. â¢ The innate system recognizes a broad range of pathogens, but it cannot make fine distinctions.
As plant roots do not reach this layer, the C horizon is typically devoid of organic matter. R Horizon (Bedrock) The R horizon is basically the deepest soil horizon in the soil profile. Unlike the horizon above, this horizon does not comprise rocks or boulders, but instead is made of continuous mass of bedrock. It is very difficult to dig through this layer.
The soil profile. As soils develop over time, layers (or horizons) form a soil profile. Most soil profiles cover the earth as 2 main layersâtopsoil and subsoil. Soil horizons are the layers in the soil as you move down the soil profile. A soil profile may have soil horizons that are easy or difficult to distinguish. Most soils exhibit 3 main horizons: 1  A horizonâhumus-rich topsoil where nutrient, organic matter and biological activity are highest (i.e. most plant roots, earthworms, insects and micro-organisms are active). 2  B horizonâclay-rich subsoil. 3  C horizonâunderlying weathered rock (from which the A and B horizons form).