Question

Differentiate between tube feet and false feet

Answer 1

Tube feet function in locomotion, feeding, and respiration. The tube feet in a starfish are arranged in grooves along the arms. ... Tube feet allow these different types of animals to stick to the ocean floor and move slowly. Tube feet consist of two parts: ampullae and podia

Answer 2

So basically tube feet are the finger like outgrowth or projections from the lower surface of skin of echinoderms which help them to crawl or stick to any surface. It also take part in some metabolic processes in their body like excretion etc.

These are permanent structures and numerous in number. Internal water circulation is an important characteristics of tube feet.  

Starfishes, brittle stars have tube feet.

On the other hand false feet can't be actually categorised as 'feet'. These are cellular outgrowth by formation of cleavage on the surface of cell membrane. These helps in engulfing food materials, excretion of cellular debris, engulfing pathogens ( shown by WBC in our blood )

So these are not permanent structure, these are readily produced when it's needed in action. Cellular organisms like Amoeba shows false feet.