I think C, correct me if I’m wrong.
Answer:
Inertia
Explanation:
Inertia is the resistance of any physical object to any change in its velocity. This includes changes to the object's speed, or direction of motion.
The most appropriate microscope for studying the internal parts of the cell is ELECTRON MICROSCOPE. The correct option is B.
Electron microscope, which is a compound microscope is usually used to study the internal environment of the cell because of the easiness with which one can easily distinguish the cell organelles from one another. Electron microscope gives great clarification of the cellular components and allow scientists to observe minute details about cellular structures. Electron microscope usually magnify specimens to one million times of their real sizes.
If the Na+ voltage-gated channels in a muscle cell open, the Na (sodium) ions rush inside the muscle cell and makes the cell more positive as Na ions carry positive charge on it. Due to the entry of positively charged ions inside the cell, the cell becomes less negative and more positive. This is called depolarization of cell.