The heart’s electrical system is responsible for making and conducting signals that trigger the heart to beat. These signals cause the heart’s muscle to contract. With each contraction, blood is pumped throughout the body. This happens 24/7 without us having to monitor it all the time so that our heart does not stop.
Stores lining cuts off unused time
Its dead plants and animals
Transporting substances in a cell. proteins are transported either in or out of the cell.
Answer:
1-C............. ...............