What are the functions of gills and the cilia on the gills?

The gill filaments are the hair-like structures on the gills which absorb the oxygen from the lamallae. The gill arch, on the other hand, acts as a form of muscle which holds the structures of the...

It works like your lungs. Lungs extract oxygen from the air just as gills extract oxygen from water. Gills can filter out water as they eat.

to breath and to protect her body

to breath

The gills of the fish help it to breath. If the gills are open, the fish id alive, but if the gills are closed, this means that it can no longer breath, and is dead.