Experiments to demonstrate importance of nucleus in controlling growth and heredity were performed on
Hammerling's nucleocytoplasmic experiments state that the cytoplasm is the centre for all the metabolic activities in the cell and the nucleus is the controlling centre.
This experiment was conducted using Acetabularia.
Acetabularia is a genus unicellular or single-celled green algae belonging to the family Polyphysaceae which are found in subtropical waters.
They are gigantic in size and complex in form, therefore, used in experiments in cell biology.
So, the correct answer is 'Acetabularia'.