<span>The phosphorus cycle is a biogeochemical cycle that describes the movement of phosphorus through the lithosphere, hydrosphere, and biosphere. Unlike many other biogeochemical cycles, the atmosphere does not play a significant role in the movement of phosphorus. Phosphorus mainly comes from soil and rock on the Earth and is recycled by living organisms</span>
Myofibrils are the building blocks or contractile unit of each muscle fiber. The tiniest functional unit of skeletal muscle, the sarcomere, is found in the myofibrils and is made up of protein filaments: actin (thin) and myosin (thick).
The process of cell reproduction consists of five stages. The first stage is called prophase. This stage occurs when the chromatin coils and condenses to form the chromosomes.In this stage the <span>nuclear membrane inside the cell begins to disappear.</span>
It has been repeatedly tested and is widely accepted.
