Their poly symmetric structure
no
Most species of desmids need mucilage so they can move.
Desmids are able to move by extruding mucilage from an apex and moving in the opposite direction.
Dens are unique to the axis.
for their color
Aristides identified Christianity as the unique feature of the Roman Empire.
A unique feature is that it has many tall towers with curving sides that taper at the top.
Desmids are a very colorful and different group of freshwater algae. They are microscopic flowerless plants. They do not have roots, stems, or leaves.
Marine
They are unique by being unique.
8=D
No idea! Srry ;