The answer is amyloid beta. They clump together and form plaques. The formed plaque can block signals transmitted from one cell to another cell. In addition, the plaque can cause swelling, especially in the area where it is formed. It can also digest the disabled cells. This type of plaque is very common among patients with Alzheimer's Disease.
The correct answer is B. pollution.
Depolarization is initiated when there is an influx of sodium inside the cell as opposed to repolarization, where potassium exits the cell (occurring after Na+ gates close). Remember that for every 3 Na+ in, there is 2 K+ out. This imbalance helps to stabilize the membrane.
Tides are caused by the location of the earth, sun and moon.
