In this article we will discuss about Flagellar Locomotion in Euglena:- 1. Introduction to Flagella in Euglena 2. Structure of Flagellum in Euglena 3. Ultrastructure 4. Role.
Introduction to Flagella in Euglena:
A common plan of organization in the non-muscular contractile system of animals is found both in flagella and cilia. These structures with certain associated fibrillar systems, provide organelles of movement not only for different protozoa, but also in many metazoan animals where that function as an important effector structure.
The effect of flagella upon the movement of a protozoa is best exemplified by Euglena — an organism, 55-100 µm in length, found swimming freely on the surface of fresh water bodies like pond, canal, lake etc.
Structure of Flagellum in Euglena:
In general, flagellum is a long whip like organ which protrudes to the exterior from the cell body and permits mechanical work without any marked change in the form of the effector cell. In Euglena, there are two flagella. One of them is equal in length to body while other is short. They emerge out through the gullet — a narrow depression at the exterior end of the spindle-shaped body.
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The gullet leads to a flask-shaped non-contractile reservoir (Fig. 2.1). The flagellum bifurcates into two at the middle of the reservoir. These two flagella originate from two compact basal granules or blepharoplasts, situated in the cytoplasm just beneath the base of the reservoir.
In most species of Euglena, the two flagella originate separately from two blepharoplasts and the shorter one soon after its emergence unites with the longer one (Fig. 2.1).
Ultrastructure of Flagellar in Euglena:
Electron microscopy has shown that the long flagellum in Euglena has two parts: