Answer:
The most significant effect of the microbes on earth is their ability to recycle the primary elements that make up all living systems, especially carbon, oxygen, and nitrogen (N). Primary production involves photosynthetic organisms which take up CO2 from the atmosphere and convert it to organic (cellular) material.
When a muscle cell contracts some myosin heads bind to actin molecules as other myosin heads release from actin molecules.
Muscle contraction occurs when the thick filament and the thin filaments slide over one another in a series of repetitive events.