Frameshift mutation (illustration). This type of mutation occurs when the addition or loss of DNA bases changes a geneâs reading frame. A reading frame consists of groups of 3 bases that each code for one amino acid. A frameshift mutation shifts the grouping of these bases and changes the code for amino acids.
Key points. 1  Soil fertility depends on three major interacting components: biological, chemical and physical fertility. 2  Soil organisms improve soil fertility by performing a number of functions that are beneficial for plants. This article examines six of these functions. Some management practices may help improve and maintain the biological fertility of soil. Releasing nutrients from organic matter. Soil microorganisms (figure 1) are responsible for most of the nutrient release from organic matter. When microorganisms decompose organic matter, they use the carbon and nutrients in the organic matter for their own growth. They release excess nutrients into the soil where they can be taken up by plants.
Bacteria are an important part of the soil. They are able to capture some nu-. trients that plants cannot. When living things die, bacteria play a very important role as. decomposers, bacteria and fungi feeding on and breaking down plant and animal matter.ou may have called it a germ, but this term only describes relatively few microorganisms. All microorganisms are living things or organisms. Microorganisms may be unicellular or single-celled, any living thing that has only one cell, the smallest unit of life.