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 A horizon is the topmost layer of the mineral soil. As it lies just below the O horizon, this layer also has some amount of humus in it and therefore, it is darker than the layers below. Similarly, the soil particles in this zone are smaller and finer compared to the lower horizons of the soil.