Question

Name the structure in a microscopic animal (such as an amoeba) that fills with water and then opens to the outside of the cell to remove excess water.

Answer 1

The structure called a contractile vacuole fills with water and contracts to expel excess water through a pore, helping organisms like amoeba regulate their internal water balance in hypotonic environments.

Step-by-step explanation:

The structure in a microscopic animal, such as an amoeba, that fills with water and then opens to the outside of the cell to remove excess water is called a contractile vacuole. Organisms that live in a hypotonic environment, such as freshwater, need a way to prevent their cells from taking in too much water by osmosis. This is where the contractile vacuole comes into play. It is surrounded by several canals, which absorb water from the cytoplasm by osmosis. Once the canals are full, the water is pumped into the vacuole. When the vacuole is full, it contracts and pushes the water out of the cell through a pore, therefore regulating the water content within the protozoan cell.