Question

What are the major mechanisms of locomotion found in protista? Name the structures which help in locomotion in protists.

Answer 1

Five modes of locomotion are recognised in the protista: pseudopodial, flagellar, ciliary, wriggling and mucilage propulsion.

1. Pseudopodial Locomotion: It is slow creeping type of locomotion which is performed with the help of protoplasmic outgrowths called pseudopodia. This type of locomotion occurs in sarcodines and slime moulds.
2. Flagellar Locomotion: Flagella show whip-like movement. They usually beat independently. This type of locomotion occurs in dinoflagellates (e.g., Gonyaulax), euglenoids (e.g., Euglena) and zooflagellates (e.g., Leishmania).
3. Ciliary Locomotion: Cilia show oar-like movement. All the cilia of a cell show coordinated movements which are of two types, isochronic and metachronic rhythms. Ciliary locomotion occurs in ciliates (e.g., Paramecium).
4. Wriggling Locomotion: It is slow worm-like movement which is performed with the help of a wave of contraction and expansion in the body, e.g, sporozoans, non-flagellates, euglenoids.
5. Locomotion by mucilage propulsion: Some protists like diatoms do not have any organelles of locomotion. They can, however, move from one place to another through secretion of mucilage. This type of locomotion occurs in the direction opposite to that of mucilage secretion.