Answer:
Explanation:
Muscle contraction is stimulated by the movement of an action potential moving along a nerve fiber to the muscles. This event follow some series of process before being stimulated.
1. The impulse arrives at the synapse and travels through the transverse tubules.
2. The muscle impulse reaches the sarcoplasmic reticulum and calcium is released.
3. Calcium floods the sarcoplasm and binds to troponin molecules leaving active sites.
4. Tropomyosin molecules bind to exposed active sites, linking actin and myosin.
5. Thin filaments are pulled over the thick filaments.
6. The muscle fiber shortens and contracts.
Protons are located C) in the nucleus with neutrons. Hope this helps!
The correct answer is a nutrient runoff.
Nutrient runoff is a major reason for eutrophication of surface waters, in which extra amount of nutrients, generally phosphorus or nitrogen, instigate growth of algae. Sources of nutrient pollution involve surface runoff from pastures and farm fields, emissions from combustion, and discharges from septic tanks.
B. The water is likely contaminated with high levels of pollution or waste