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.
Worms play an important part in soil construction and recycling of organic waste. They are a part of a network of organisms that turn refuse into nutrient rich soil. These nutrients are one of the benefits of garden worms to plant growth. Worms in gardens also perform cultivation functions that increase soil porosity and allow oxygen to get into roots. Encourage earthworms in soil or even try worm composting to experience the life-giving effects of worm castings. Earthworm Benefits. Worms tunnel in soil and eat organic matter, which they excrete as castings. Worms abound in soils that are around 70 degrees Fahrenheit (21 C.). Any extremes of cold, heat or moisture are not good for worm activity. Worms in gardens are most active when soil is moderately warm and moist.