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.
When the microbes cause diseases, however, uncontrolled growth can lead to people becoming more sick or dying. In laboratories that work with microbes, controlling their growth is essential for obtaining useful experimental results.n order to be effective, though, the ethanol must be left on the surface long enough to kill the microbes. Radiation is also effective at killing microbes. One common type of radiation used is ultraviolet, the same type that is found in sunlight.