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.
Answer:
if sex cells were identical, there won't be genetics variations and we will just all be identical to our parents. genetic variation allows us to better adapt and survive
The cell actually divides in Cytokinesis.
