Answer:
The valves' main job is to keep the blood moving in one direction – back up towards the heart. When the valve is open, blood freely flows upward towards the heart and when the valves are closed, blood cannot flow back
<span>An organism may not be able to survive on just fermentation because the fermentation process does not produce very much energy. If an organism were to be able to survive on fermentation alone, the organism would have to be extremely small.</span>
Answer:
The correct answer is C: competition for resources
Answer:
Explanation:
This protein makes up part of the sarcomere and forms macromolecular filaments composed of multiple myosin subunits. Similar filament-forming myosin proteins were found in cardiac muscle, smooth muscle, and nonmuscle cells.