Parts that cannot be digested are simply left behind as the amoeba swims. When the amoeba drinks fluids they are drawn into the channels and absorbed into the protoplasm in the same way digested foods are. This allows the cell to absorb fluids in bulk. The amoeba is continually drawing water in and passing it through the cell membrane. The excess water is pumped out by contractile vacuoles which fill with water and then collapse causing the water to discharge to the outside.
Amoebas reproduce themselves by dividing into two equal parts.
This process is known as binary fission and takes less than one hour. When it begins the amoeba becomes spherical as the nucleus divides into two parts. The two halves then move apart and the cell splits down the middle. In some cases, such as the amoeba proteus, the reproduction is done in a different manner. Their nucleus will divide into hundreds of smaller nucleus, which is then surrounded by a little cytoplasm and a tough wall.