Cilia and flagella in eukaryotes are similar in structure but vary in number, le

a.   One or few flagella may be present, while cilia are present in large numbers.
b.   Flagella are generally longer than cilia.
c.   Flagella generate a force parallel to the axis of the appendage, while cilia generate a force perpendicular to the axis.
d.   The function of flagella in both multicellular and unicellular eukaryotes is the movement of the cell. This is also the case for unicellular cells with cilia, while multicellular organisms use cilia to move the environment rather than the cell. 
e.   The motion of flagella is symmetrical and undulatory. The student may suggest that the motion is like a propeller or like an outboard motor. Cilia display an oarlike pattern of beating.