In the amoeba, water input and output are controlled by the nucleus food vacuole vacuole pseudopodia

The correct answer for the fill in the blank is-  Vacuole.

Vacuole or contractile vacuole is a specialised subcellular organelle that is responsible for osmoregulation ( balance of water and electrolyte concentration).

For instance, in freshwater environment ( which is hypotonic), it allows the water to accumulate inside the cell.

It is predominantly found in protists ( such as Amoeba and Paramecium) and unicellular algae. It prevents the organism from rupturing or lysing as it controls the input and output of water.

what school and grade?

the correct answer is b