Question

Sponges have a _____ that squeezes out waste.

Answer 1

Contractile Vacuole, s a sub-cellular structure (organelle) involved in osmoregulation.

Osmoregulation is the active regulation of the osmotic pressure of an organism's fluids to maintain the homeostasis of the organism's water content.

Answer 2

contractile vacuole A membrane-surrounded cavity in a cell that periodically expands, filling with water, and then suddenly contracts, expelling its contents to the cell's exterior. It is thus an organ of osmoregulation and excretion. Contractile vacuoles are common in freshwater sponges and typical of freshwater protoctists, such as Amoeba (which has one spherical vacuole) and Paramecium (in which a number of accessory vacuoles are attached to a main vacuole).