Unicellular organisms excrete waste by a contractile vacuole. A vacuole is membrane-enveloped organelle in a cell that is found in lots of microorganism. It expands, filling with water then contracts, removing all of its contents to the exterior of the cell.
C. Permafrost
Permafrost is the layer beneath the "active layer". The active layer consists of soil that freezes and thaws every year. However, the requirement for permafrost is that it be frozen for two or more years consecutively. This is why permafrost exists in cold environments such as tundras.
I think it 700 million years because I took the same question and that’s what I put.
Answer:
<h2>
Vacuoles</h2>
Explanation:
Vacuoles (located in the cell), store water, food and waste. It acts as a storage unit for the cell.
