Answer:
It lacks a wall thus use the contractile vacuole to collect and expel excess water from the cell.
Explanation:
- The contractile vacuole regulates the quantity of water inside a cell through a process known as osmoregulation.Osmosis constantly drives water in the cell since it is enclosed by a semipermeable membrane that can not keep the water out thus it is needed to prevent rupturing of the cell due to excess water in the cell.
They don't have the same properties of a star fish
I think it’s thermosphere :)