Soil scientists use the capital letters O, A, B, C, and E to identify the master soil horizons<span>, and lowercase letters for distinctions of these horizons. Most soils have three major horizons: the surface horizon (A), the subsoil (B), and the substratum (C). Some soils have an organic horizon (O) on the surface, but such a horizon can also be buried. The master horizon, E, is used for subsurface horizons that have a significant loss of minerals (eluviation). Hard bedrock, which is not soil, uses the letter R.</span>
Catalysts or if it’s in the body it’s usually a biological catalyst called enzymes, all catalysts speed up reactions without being changed or changing the reaction
Stomata is present at epidermis of the leaves lenticels are present at bark
